Change CGDebugInfo::setLocation to just ignore invalid locations. This
simplifies clients.

Also, add assert that RegionStack is empty when the CGDebugInfo is
destroyed.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57684 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed