test/Driver/prefixed-tools.c: Disable this on win32 hosts, msvc and mingw.

It had failed on Win32 due to inability of executing shell scripts.
Still it fails even with mingw MSYS bash.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149100 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed