[Bug c++/122259] Enhance assignment to a const member compiler error message

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122259

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Displaying less information is not generally a good idea. Other people want
that information, and there are times it's essential.