[PATCH] D29464: [MinGWToolChain] Don't use GCC headers on Win32

[Mateusz Mikuła via Phabricator via cfe-commits]

mati865 added a comment.

Adding

  // c:\mingw32\lib\gcc\i686-w64-mingw32\4.9.1\include
  // c:\mingw32\lib\gcc\i686-w64-mingw32\4.9.1\include-fixed

for Clang is wrong on Windows because including limits.h will not show an error and won't really include mingw-w64 limits.h
Output of code from my earlier comment without patch:

  error: use of undeclared identifier 'PATH_MAX'
  int main() { char buf[PATH_MAX]; }

I haven't used cross compiled Clang on Linux so I added #ifndef LLVM_ON_WIN32 guard for this code.
With this guard Clang on Windows uses include paths like native Clang on Linux

Include directories on public paste: https://reviews.llvm.org/P7968


https://reviews.llvm.org/D29464