[Sema] Remove dead typedef

rdar://problem/28988750

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@292635 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 14abaea43b00f28bcd9f71381f562dcf05dc0a96)
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index b705266..edc9c68 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -3143,7 +3143,6 @@
                              bool IsProtocolMethodDecl);
 
   typedef llvm::SmallPtrSet<Selector, 8> SelectorSet;
-  typedef llvm::DenseMap<Selector, ObjCMethodDecl*> ProtocolsMethodsMap;
 
   /// CheckImplementationIvars - This routine checks if the instance variables
   /// listed in the implelementation match those listed in the interface.