diff --git a/lib/CodeGen/ConstantBuilder.h b/include/clang/CodeGen/ConstantInitBuilder.h
similarity index 76%
rename from lib/CodeGen/ConstantBuilder.h
rename to include/clang/CodeGen/ConstantInitBuilder.h
index 40b34a9..5c1a8d3 100644
--- a/lib/CodeGen/ConstantBuilder.h
+++ b/include/clang/CodeGen/ConstantInitBuilder.h
@@ -1,4 +1,4 @@
-//===----- ConstantBuilder.h - Builder for LLVM IR constants ----*- C++ -*-===//
+//===- ConstantInitBuilder.h - Builder for LLVM IR constants ----*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,24 +8,26 @@
 //===----------------------------------------------------------------------===//
 //
 // This class provides a convenient interface for building complex
-// global initializers.
+// global initializers of the sort that are frequently required for
+// language ABIs.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CLANG_LIB_CODEGEN_CONSTANTBUILDER_H
-#define LLVM_CLANG_LIB_CODEGEN_CONSTANTBUILDER_H
+#ifndef LLVM_CLANG_CODEGEN_CONSTANTINITBUILDER_H
+#define LLVM_CLANG_CODEGEN_CONSTANTINITBUILDER_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/IR/Constants.h"
-
-#include "CodeGenModule.h"
+#include "llvm/IR/GlobalValue.h"
+#include "clang/AST/CharUnits.h"
 
 #include <vector>
 
 namespace clang {
 namespace CodeGen {
 
+class CodeGenModule;
 class ConstantStructBuilder;
 class ConstantArrayBuilder;
 
@@ -144,9 +146,7 @@
     }
 
     /// Add an integer value of type size_t.
-    void addSize(CharUnits size) {
-      add(Builder.CGM.getSize(size));
-    }
+    void addSize(CharUnits size);
 
     /// Add an integer value of a specific type.
     void addInt(llvm::IntegerType *intTy, uint64_t value,
@@ -165,7 +165,7 @@
     }
 
     /// Add a bunch of new values to this initializer.
-    void addAll(ArrayRef<llvm::Constant *> values) {
+    void addAll(llvm::ArrayRef<llvm::Constant *> values) {
       assert(!Finished && "cannot add more values after finishing builder");
       assert(!Frozen && "cannot add values while subbuilder is active");
       Builder.Buffer.append(values.begin(), values.end());
@@ -216,20 +216,9 @@
     ///
     /// The returned pointer will have type T*, where T is the given
     /// position.
-    llvm::Constant *getAddrOfCurrentPosition(llvm::Type *type) {
-      // Make a global variable.  We will replace this with a GEP to this
-      // position after installing the initializer.
-      auto dummy =
-        new llvm::GlobalVariable(Builder.CGM.getModule(), type, true,
-                                 llvm::GlobalVariable::PrivateLinkage,
-                                 nullptr, "");
-      Builder.SelfReferences.emplace_back(dummy);
-      auto &entry = Builder.SelfReferences.back();
-      (void) getGEPIndicesToCurrentPosition(entry.Indices);
-      return dummy;
-    }
+    llvm::Constant *getAddrOfCurrentPosition(llvm::Type *type);
 
-    ArrayRef<llvm::Constant*> getGEPIndicesToCurrentPosition(
+    llvm::ArrayRef<llvm::Constant*> getGEPIndicesToCurrentPosition(
                              llvm::SmallVectorImpl<llvm::Constant*> &indices) {
       getGEPIndicesTo(indices, Builder.Buffer.size());
       return indices;
@@ -240,23 +229,7 @@
 
   private:
     void getGEPIndicesTo(llvm::SmallVectorImpl<llvm::Constant*> &indices,
-                         size_t position) const {
-      // Recurse on the parent builder if present.
-      if (Parent) {
-        Parent->getGEPIndicesTo(indices, Begin);
-
-      // Otherwise, add an index to drill into the first level of pointer. 
-      } else {
-        assert(indices.empty());
-        indices.push_back(llvm::ConstantInt::get(Builder.CGM.Int32Ty, 0));
-      }
-
-      assert(position >= Begin);
-      // We have to use i32 here because struct GEPs demand i32 indices.
-      // It's rather unlikely to matter in practice.
-      indices.push_back(llvm::ConstantInt::get(Builder.CGM.Int32Ty,
-                                               position - Begin));
-    }
+                         size_t position) const;
   };
 
   template <class Impl>
@@ -313,36 +286,12 @@
                                      bool constant = false,
                                      llvm::GlobalValue::LinkageTypes linkage
                                        = llvm::GlobalValue::InternalLinkage,
-                                     unsigned addressSpace = 0) {
-    auto GV = new llvm::GlobalVariable(CGM.getModule(),
-                                       initializer->getType(),
-                                       constant,
-                                       linkage,
-                                       initializer,
-                                       name,
-                                       /*insert before*/ nullptr,
-                                       llvm::GlobalValue::NotThreadLocal,
-                                       addressSpace);
-    GV->setAlignment(alignment.getQuantity());
-    resolveSelfReferences(GV);
-    return GV;
-  }
+                                     unsigned addressSpace = 0);
 
   void setGlobalInitializer(llvm::GlobalVariable *GV,
-                            llvm::Constant *initializer) {
-    GV->setInitializer(initializer);
-    resolveSelfReferences(GV);
-  }
+                            llvm::Constant *initializer);
 
-  void resolveSelfReferences(llvm::GlobalVariable *GV) {
-    for (auto &entry : SelfReferences) {
-      llvm::Constant *resolvedReference =
-        llvm::ConstantExpr::getInBoundsGetElementPtr(
-          GV->getValueType(), GV, entry.Indices);
-      entry.Dummy->replaceAllUsesWith(resolvedReference);
-      entry.Dummy->eraseFromParent();
-    }
-  }
+  void resolveSelfReferences(llvm::GlobalVariable *GV);
 };
 
 /// A helper class of ConstantInitBuilder, used for building constant
@@ -370,20 +319,7 @@
 private:
   /// Form an array constant from the values that have been added to this
   /// builder.
-  llvm::Constant *finishImpl() {
-    markFinished();
-
-    auto &buffer = getBuffer();
-    assert((Begin < buffer.size() ||
-            (Begin == buffer.size() && EltTy))
-           && "didn't add any array elements without element type");
-    auto elts = llvm::makeArrayRef(buffer).slice(Begin);
-    auto eltTy = EltTy ? EltTy : elts[0]->getType();
-    auto type = llvm::ArrayType::get(eltTy, elts.size());
-    auto constant = llvm::ConstantArray::get(type, elts);
-    buffer.erase(buffer.begin() + Begin, buffer.end());
-    return constant;
-  }
+  llvm::Constant *finishImpl();
 };
 
 inline ConstantArrayBuilder
@@ -408,23 +344,7 @@
     : AggregateBuilder(builder, parent), Ty(ty) {}
 
   /// Finish the struct.
-  llvm::Constant *finishImpl() {
-    markFinished();
-
-    auto &buffer = getBuffer();
-    assert(Begin < buffer.size() && "didn't add any struct elements?");
-    auto elts = llvm::makeArrayRef(buffer).slice(Begin);
-
-    llvm::Constant *constant;
-    if (Ty) {
-      constant = llvm::ConstantStruct::get(Ty, elts);
-    } else {
-      constant = llvm::ConstantStruct::getAnon(elts, /*packed*/ false);
-    }
-
-    buffer.erase(buffer.begin() + Begin, buffer.end());
-    return constant;
-  }
+  llvm::Constant *finishImpl();
 };
 
 inline ConstantStructBuilder
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index b250b9a..227f0cd 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -16,7 +16,7 @@
 #include "CGObjCRuntime.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/DeclObjC.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/IR/CallSite.h"
diff --git a/lib/CodeGen/CGCUDANV.cpp b/lib/CodeGen/CGCUDANV.cpp
index 83febcb..813cd74 100644
--- a/lib/CodeGen/CGCUDANV.cpp
+++ b/lib/CodeGen/CGCUDANV.cpp
@@ -15,7 +15,7 @@
 #include "CGCUDARuntime.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/Decl.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CallSite.h"
diff --git a/lib/CodeGen/CGObjCGNU.cpp b/lib/CodeGen/CGObjCGNU.cpp
index fa2b3d8..ce39bd1 100644
--- a/lib/CodeGen/CGObjCGNU.cpp
+++ b/lib/CodeGen/CGObjCGNU.cpp
@@ -18,7 +18,7 @@
 #include "CGCleanup.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclObjC.h"
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 01793e2..2880733 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -17,7 +17,7 @@
 #include "CGRecordLayout.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclObjC.h"
diff --git a/lib/CodeGen/CGOpenMPRuntime.cpp b/lib/CodeGen/CGOpenMPRuntime.cpp
index 4025217..e54cf7b 100644
--- a/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -15,7 +15,7 @@
 #include "CGCleanup.h"
 #include "CGOpenMPRuntime.h"
 #include "CodeGenFunction.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/StmtOpenMP.h"
 #include "llvm/ADT/ArrayRef.h"
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index 1a09830..64a3d2d 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -14,7 +14,7 @@
 #include "CGCXXABI.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
diff --git a/lib/CodeGen/CMakeLists.txt b/lib/CodeGen/CMakeLists.txt
index 4fbf9f2..921e3b8 100644
--- a/lib/CodeGen/CMakeLists.txt
+++ b/lib/CodeGen/CMakeLists.txt
@@ -75,6 +75,7 @@
   CodeGenPGO.cpp
   CodeGenTBAA.cpp
   CodeGenTypes.cpp
+  ConstantInitBuilder.cpp
   CoverageMappingGen.cpp
   ItaniumCXXABI.cpp
   MicrosoftCXXABI.cpp
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index a6b2559..44967ae 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -24,7 +24,6 @@
 #include "CodeGenFunction.h"
 #include "CodeGenPGO.h"
 #include "CodeGenTBAA.h"
-#include "ConstantBuilder.h"
 #include "CoverageMappingGen.h"
 #include "TargetInfo.h"
 #include "clang/AST/ASTContext.h"
@@ -42,6 +41,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/Version.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/Frontend/CodeGenOptions.h"
 #include "clang/Sema/SemaDiagnostic.h"
 #include "llvm/ADT/Triple.h"
diff --git a/lib/CodeGen/ConstantInitBuilder.cpp b/lib/CodeGen/ConstantInitBuilder.cpp
new file mode 100644
index 0000000..772391e
--- /dev/null
+++ b/lib/CodeGen/ConstantInitBuilder.cpp
@@ -0,0 +1,131 @@
+//===--- ConstantInitBuilder.cpp - Global initializer builder -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines out-of-line routines for building initializers for
+// global variables, in particular the kind of globals that are implicitly
+// introduced by various language ABIs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CodeGen/ConstantInitBuilder.h"
+#include "CodeGenModule.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+llvm::GlobalVariable *
+ConstantInitBuilder::createGlobal(llvm::Constant *initializer,
+                                  const llvm::Twine &name,
+                                  CharUnits alignment,
+                                  bool constant,
+                                  llvm::GlobalValue::LinkageTypes linkage,
+                                  unsigned addressSpace) {
+  auto GV = new llvm::GlobalVariable(CGM.getModule(),
+                                     initializer->getType(),
+                                     constant,
+                                     linkage,
+                                     initializer,
+                                     name,
+                                     /*insert before*/ nullptr,
+                                     llvm::GlobalValue::NotThreadLocal,
+                                     addressSpace);
+  GV->setAlignment(alignment.getQuantity());
+  resolveSelfReferences(GV);
+  return GV;
+}
+
+void ConstantInitBuilder::setGlobalInitializer(llvm::GlobalVariable *GV,
+                                               llvm::Constant *initializer) {
+  GV->setInitializer(initializer);
+
+  if (!SelfReferences.empty())
+    resolveSelfReferences(GV);
+}
+
+void ConstantInitBuilder::resolveSelfReferences(llvm::GlobalVariable *GV) {
+  for (auto &entry : SelfReferences) {
+    llvm::Constant *resolvedReference =
+      llvm::ConstantExpr::getInBoundsGetElementPtr(
+        GV->getValueType(), GV, entry.Indices);
+    entry.Dummy->replaceAllUsesWith(resolvedReference);
+    entry.Dummy->eraseFromParent();
+  }
+}
+
+void ConstantInitBuilder::AggregateBuilderBase::addSize(CharUnits size) {
+  add(Builder.CGM.getSize(size));
+}
+
+llvm::Constant *
+ConstantInitBuilder::AggregateBuilderBase::getAddrOfCurrentPosition(
+                                                            llvm::Type *type) {
+  // Make a global variable.  We will replace this with a GEP to this
+  // position after installing the initializer.
+  auto dummy =
+    new llvm::GlobalVariable(Builder.CGM.getModule(), type, true,
+                             llvm::GlobalVariable::PrivateLinkage,
+                             nullptr, "");
+  Builder.SelfReferences.emplace_back(dummy);
+  auto &entry = Builder.SelfReferences.back();
+  (void) getGEPIndicesToCurrentPosition(entry.Indices);
+  return dummy;
+}
+
+void ConstantInitBuilder::AggregateBuilderBase::getGEPIndicesTo(
+                               llvm::SmallVectorImpl<llvm::Constant*> &indices,
+                               size_t position) const {
+  // Recurse on the parent builder if present.
+  if (Parent) {
+    Parent->getGEPIndicesTo(indices, Begin);
+
+  // Otherwise, add an index to drill into the first level of pointer. 
+  } else {
+    assert(indices.empty());
+    indices.push_back(llvm::ConstantInt::get(Builder.CGM.Int32Ty, 0));
+  }
+
+  assert(position >= Begin);
+  // We have to use i32 here because struct GEPs demand i32 indices.
+  // It's rather unlikely to matter in practice.
+  indices.push_back(llvm::ConstantInt::get(Builder.CGM.Int32Ty,
+                                           position - Begin));
+}
+
+llvm::Constant *ConstantArrayBuilder::finishImpl() {
+  markFinished();
+
+  auto &buffer = getBuffer();
+  assert((Begin < buffer.size() ||
+          (Begin == buffer.size() && EltTy))
+         && "didn't add any array elements without element type");
+  auto elts = llvm::makeArrayRef(buffer).slice(Begin);
+  auto eltTy = EltTy ? EltTy : elts[0]->getType();
+  auto type = llvm::ArrayType::get(eltTy, elts.size());
+  auto constant = llvm::ConstantArray::get(type, elts);
+  buffer.erase(buffer.begin() + Begin, buffer.end());
+  return constant;
+}
+
+llvm::Constant *ConstantStructBuilder::finishImpl() {
+  markFinished();
+
+  auto &buffer = getBuffer();
+  assert(Begin < buffer.size() && "didn't add any struct elements?");
+  auto elts = llvm::makeArrayRef(buffer).slice(Begin);
+
+  llvm::Constant *constant;
+  if (Ty) {
+    constant = llvm::ConstantStruct::get(Ty, elts);
+  } else {
+    constant = llvm::ConstantStruct::getAnon(elts, /*packed*/ false);
+  }
+
+  buffer.erase(buffer.begin() + Begin, buffer.end());
+  return constant;
+}
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 490fadb..fe1fbd1 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -24,8 +24,8 @@
 #include "CGVTables.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
-#include "ConstantBuilder.h"
 #include "TargetInfo.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/Mangle.h"
 #include "clang/AST/Type.h"
 #include "clang/AST/StmtCXX.h"
diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index 38df455..ac9f8d3 100644
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -19,8 +19,8 @@
 #include "CGVTables.h"
 #include "CodeGenModule.h"
 #include "CodeGenTypes.h"
-#include "ConstantBuilder.h"
 #include "TargetInfo.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/StmtCXX.h"