Now that the underlying issue is fixed, revert r180750 and r180722.

The cause of the windows failures was fixed by r180791. Revert to the state
after Sabre's original revert.

Original message:

revert r179735, it has no testcases, and doesn't really make sense.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180844 91177308-0d34-0410-b5e6-96231b3b80d8