- r127238 mingw-w64 should define __MINGW32__, too.

 - r127329 declarations of __builtin_ia32_crc32**()
 - r127652 Tweak InitHeaderSearch.cpp for mingw-w64-gcc
 - r127654 _mm_malloc tweak
 - r127655 Tweak __declspec and __attribute__ for mingw

--- Merging r127238 into '.':
U    lib/Basic/Targets.cpp
--- Merging r127329 into '.':
A    test/Sema/builtins-decl.c
U    include/clang/Basic/BuiltinsX86.def
--- Merging r127652 into '.':
U    lib/Frontend/InitHeaderSearch.cpp
--- Merging r127654 into '.':
U    lib/Headers/mm_malloc.h
--- Merging r127655 into '.':
G    lib/Basic/Targets.cpp

llvm-svn: 128046