Fixing a bug where debug info for a local variable gets emitted at file scope.

The patch was discussed in Phabricator. See:
http://llvm-reviews.chandlerc.com/D1281



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189649 91177308-0d34-0410-b5e6-96231b3b80d8