[Bug c++/125212] ICE when using lambdas as alias template parameters

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125212

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Yes, we have:

 <typename_type 0x7fffe99e9690 Alias1 tree_0 tree_2 VOID
    align:8 warn_if_not_align:0 symtab:0 alias-set -1 structural-equality
context <template_type_parm 0x7fffe99cb888 T>
    fullname <template_id_expr 0x7fffe99e6640
        arg:0 <identifier_node 0x7fffe99e2100 Alias
            normal local bindings <(nil)>>
        arg:1 <tree_vec 0x7fffe99c6e80 length:1
            elt:0 <lambda_expr 0x7fffe99e7000 type <record_type 0x7fffe99cbb28
._anon_0>
                tree_1 default_capture_mode=[NONE] >>
        125212.C:19:32 start: 125212.C:19:32 finish: 125212.C:19:55>
    chain <type_decl 0x7fffe99e4820 Alias>>


but the LAMBDA_EXPR is nested too deeply for any_lambda_targ_p to catch it.  So
I think we want a flag in TYPE_DECL.  Poking more...