Extend the macro-expansion refactoring to work with member and
member-attribute attached macros. These expansions can return several
different changes, e.g., adding new members, sprinkling member
attributes around, and so on.
- Use the name lookup table instead of adding members from a macro expansion to the parent decl context.
- Require declaration macros to specify introduced names and used the declared names to guide macro expansions lazily.
