[Bug c++/93689] ICE with default argument in lambda used as non type template argument

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93689

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
The test was rejected with various errors, then with
r9-4045-g0c1e0d63fe0ceabbd04384070f3b59f8bf50de09 we got this ICE:

93689.C: In function ‘int f() [with auto Z = <lambda closure
object>main()::<lambda(int)>{}]’:
93689.C:5:13: internal compiler error: in gimplify_expr, at gimplify.c:12491
    5 |     return Z();
      |            ~^~
0x6dbdf3 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/mpolacek/src/gcc9/gcc/gimplify.c:12491
0xceaa9d gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
        /home/mpolacek/src/gcc9/gcc/gimplify.c:13226
0xcf3ce4 gimplify_expr
        /home/mpolacek/src/gcc9/gcc/gimplify.c:13512
0xcf5965 gimplify_call_expr
        /home/mpolacek/src/gcc9/gcc/gimplify.c:3405
...

and since r10-6527-gaaa26bf496a646778ac861aed124d960b5bf549f the ICE in Comment
1.