DebugInfo: Support (using GNU extensions) for template template parameters and parameter packs

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184643 91177308-0d34-0410-b5e6-96231b3b80d8
Replace with a shorter test case produced by Doug Gillmore.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184645 91177308-0d34-0410-b5e6-96231b3b80d8