Revert r205551, "Attempt to XFAIL this on mingw and cygwin hosts." It didn't fail on cygming.

That said, it emits errors to the stderr (with exit(0));

  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_DIR32
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_DIR32
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_SECREL
  error: failed to compute relocation: IMAGE_REL_I386_DIR32

llvm-svn: 205560