Temporarily revert r183462: "Implement DR7"

This fixes PR16370, I'll add the test case in a follow-up commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184401 91177308-0d34-0410-b5e6-96231b3b80d8
Add a regression test for PR16370 next to the dr7 test case since they
seem closely related. (I'm happy to move this if others have a better
idea of where to put it.)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184402 91177308-0d34-0410-b5e6-96231b3b80d8