Push nested-name-specifier source-location information into dependent
template specialization types. There are still a few rough edges to
clean up with some of the parser actions dropping
nested-name-specifiers too early.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126776 91177308-0d34-0410-b5e6-96231b3b80d8