[Bug c++/77777] Use rich location to mark correct expression for "invalid use of non-static member function"

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77777

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Or maybe even better, make the caret point to the member function, but cover
the entire expression:

      x.foo
      ~~^~~


(Please ignore the "did you mean...?" part shown in the initial comment, that
was produced by a locally patched gcc, but is not relevant to this bug).