According to the dwarf standard pubnames and pubtypes for languages

According to the dwarf standard pubnames and pubtypes for languages
like C++ should be the fully qualified names for the type.

Add a routine that does a language specific context walk to build
up the qualified name and use it when we add types/names to the
tables. Expand the gnu pubnames testcase as it's the most complex
to make sure that qualified types are also being added.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192865 91177308-0d34-0410-b5e6-96231b3b80d8