test/lit.cfg: Please pass %INCLUDE% to clang.exe on Win32. MS-compatible clang may refer to %INCLUDE%. It fixes r154188.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154240 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed