[Bug c++/81636] Confusing warning message containing "#‘obj_type_ref’ not supported by expression#"

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81636

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Paolo added FIX_TRUNC_EXPR and FLOAT_EXPR to dump_expr in r143790, but I
believe we need more than just pp->expression (t);, we need to print it
similarly to CONVERT_EXPR.