[Bug c++/105202] New: ICE: defaulted comparison operators for enumerated types segfault

[falbrechtskirchinger at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105202

            Bug ID: 105202
           Summary: ICE: defaulted comparison operators for enumerated
                    types segfault
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: falbrechtskirchinger at gmail dot com
  Target Milestone: ---

Versions:
g++
(Compiler-Explorer-Build-gcc-45fb78c9c456ace1d914c836d15af38ae345b902-binutils-2.36.1)
12.0.1 20220407 (experimental)
g++-12.0.1 (Gentoo 12.0.1 p2, commit d43fbc7d3f7621e1c8f153c1471d2a5cd20bfdc8)
12.0.1 20220201 (experimental)

Code:
enum class foo {};
bool operator<(foo, foo) = default;

Compile with: g++ -std=c++20

Error:
ice_defaulted_operator.cpp:2:28: internal compiler error: Segmentation fault
    2 | bool operator<(foo, foo) = default;
      |                            ^~~~~~~

Stack trace from Compiler Explorer:
0x218e8e9 internal_error(char const*, ...)
        ???:0
0x146ee90 strip_array_types(tree_node*)
        ???:0
0xa7c328 cp_type_quals(tree_node const*)
        ???:0
0xa6d323 cp_build_qualified_type_real(tree_node*, int, int)
        ???:0
0x8cbf04 defaultable_fn_check(tree_node*)
        ???:0
0x84c170 cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int)
        ???:0
0x9870ad c_parse_file()
        ???:0
0xb196e2 c_common_parse_file()
        ???:0

Comparison with other compilers:
https://godbolt.org/z/qnq5Gnqc5

This obviously shouldn't segfault. Clang seems to give the most reasonable
error message.