[Bug middle-end/126912] Match vs compare simplifications

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126912

--- Comment #4 from Drea Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Drea Pinski from comment #3)
> Created attachment 65350 [details]
> Patch which I am testing
> 
> I have to look into the internals manual to see if there is anything that
> needs to be updated here.  But this seems to work. There is no extra checks
> that just says the c_expr here can only be a tcc_comparison in the generated
> code; this is something which I am thinking about adding. Because I assume
> it is in genmatch when it comes to the type.

I have one bug in parser::parse_operation where I should have moved the
initialization of opt_grp in front of the id_tok->type == CPP_OPEN_BRACE check.
Without that you get a "random" rejection.  I am testing with the fix.