members of dependent contexts.
This permits cases where the names before and after the '::' in a
dependent inherited constructor using-declaration do not match, but
where we can nonetheless tell when parsing the template that a
constructor is being named. Under (open) core language DR 2070, such
cases will probably be ill-formed, but r335182 does not quite give
that result and didn't intend to change this, so restore the old
behavior for now.
llvm-svn: 335381