It was marked as unsupported on Windows in r311230 because on some Win10
machines it failed or caused hang. The problem was that on these machines
system bash (C:\Windows\System32\bash.exe) was used which requires paths to be
passed like '/mnt/c/path/to/my/script' instead of 'C:\path\to\my\script'.
TODO: we should make lit detect if system bash is used instead of msys and set
appropriate path format.
llvm-svn: 311558
9f11c0bddf