Merge remote-tracking branch 'origin/swift-3.1-branch' into stable

* origin/swift-3.1-branch:
  Revert "[Headers] Enable #include_next<float.h> on Darwin"
diff --git a/lib/Headers/float.h b/lib/Headers/float.h
index 0f453d8..a28269e 100644
--- a/lib/Headers/float.h
+++ b/lib/Headers/float.h
@@ -27,12 +27,9 @@
 /* If we're on MinGW, fall back to the system's float.h, which might have
  * additional definitions provided for Windows.
  * For more details see http://msdn.microsoft.com/en-us/library/y0ybw9fy.aspx
- *
- * Also fall back on Darwin to allow additional definitions and
- * implementation-defined values.
  */
-#if (defined(__APPLE__) || (defined(__MINGW32__) || defined(_MSC_VER))) && \
-    __STDC_HOSTED__ && __has_include_next(<float.h>)
+#if (defined(__MINGW32__) || defined(_MSC_VER)) && __STDC_HOSTED__ && \
+    __has_include_next(<float.h>)
 #  include_next <float.h>
 
 /* Undefine anything that we'll be redefining below. */
diff --git a/test/Headers/Inputs/usr/include/float.h b/test/Headers/Inputs/usr/include/float.h
deleted file mode 100644
index 9dab891..0000000
--- a/test/Headers/Inputs/usr/include/float.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef SYSFLOAT_H
-#define SYSFLOAT_H
-
-#define FLT_HAS_SUBNORM 1
-
-#endif /* SYSFLOAT_H */
diff --git a/test/Headers/float-darwin.c b/test/Headers/float-darwin.c
deleted file mode 100644
index 54bac1a..0000000
--- a/test/Headers/float-darwin.c
+++ /dev/null
@@ -1,13 +0,0 @@
-// REQUIRES: system-darwin
-// RUN: %clang -target x86_64-apple-darwin10 -fsyntax-only -std=c11 -isysroot %S/Inputs %s
-#include <float.h>
-
-// Test the #include_next on float.h works on Darwin.
-#ifndef FLT_HAS_SUBNORM
-  #error "FLT_HAS_SUBNORM not defined"
-#endif
-
-// Test that definition from builtin are also present.
-#ifndef FLT_MAX
-  #error "FLT_MAX not defined"
-#endif