This test is XFAILed on Windows, but I cannot see a reason as to why it should...

This test is XFAILed on Windows, but I cannot see a reason as to why it should be failing. The original commit which XFAILed this was r111581, which suggested something was wrong with file remapping, but that may have been subsequently fixed.

Removing the XFAIL, but will watch the build bots to see if any go red because of this. Local testing on Windows succeeds.

llvm-svn: 209130