[Bug c++/53281] poor error message for calling a non-const method from a const object

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53281

--- Comment #7 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
(In reply to David Malcolm from comment #6)
[...]
> We should also underline the param, or the "const" token.
(actually, if the member function or param is 'const', it's not a problem, I
think.  -ENOCOFFEE)