Rollup merge of #144268 - xizheyin:find-oldest-ancestor, r=jieyouxu

Add method `find_ancestor_not_from_macro` and `find_ancestor_not_from_extern_macro` to supersede `find_oldest_ancestor_in_same_ctxt`

As I was using it, I realized that the function is supposed to walk up to expand the chain? This seems to be the opposite of what I understood.

r? `@jieyouxu`

Author: Zalathar