[Bug c/113688] [14/15 Regression] verify_type fails for compatible structs with FAM in C23, builtin-sprintf-warn-1.c and gnu23-tag-1.c with -g

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113688

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to uecker from comment #3)
> The issue is that struct with ISO C99 flexible array member and GNU
> zero-sized extension will have different mode but we may want to them to be
> compatible.

it is not just GNU zero-sized extension either. it is with 1 sized arrays too
(from the dup PR 114723). So this is no longer about a GNU extension I think.

That is this ICEs too:
struct S{int x,y[0];}*a;
int main(void){
        struct S{int x,y[];};
}