Revert "Debug info: (bugfix) C++ C/Dtors can be compiled to multiple functions,"

This reverts commit 206096 while I investigate why this broke the gdb
buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206103 91177308-0d34-0410-b5e6-96231b3b80d8