Test for empty pubnames/pubtypes

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203621 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Do not emit pubnames/pubtypes sections if they are empty

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203622 91177308-0d34-0410-b5e6-96231b3b80d8