[Bug c++/107522] New: ICE in parameter_mapping_equivalent_p on trunk

[Bug c++/107522] New: ICE in parameter_mapping_equivalent_p on trunk

[gwangi.kali at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107522

            Bug ID: 107522
           Summary: ICE in parameter_mapping_equivalent_p on trunk
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gwangi.kali at gmail dot com
  Target Milestone: ---

Live Example: https://godbolt.org/z/sqTaMnYva
Command Line Args: -std=c++20
Version: Trunk

```cpp
enum class Enum { A, B };

template<Enum E>
class Class
{
public:
    template<enum Enum E2 = E>
    Class() requires (E2 == Enum::A);
};

template<>
template<enum Enum E2>
Class<Enum::A>::Class() requires (E2 == Enum::A)
{}

int main()
{
    Class<Enum::A>{};
    return 0;
}
```

```bash
Could not execute the program
Compiler returned: 1
Compiler stderr
<source>: In instantiation of 'Class<E>::Class() requires  E2 == Enum::A [with
Enum E2 = Enum::A; Enum E = Enum::A]':
<source>:18:20:   required from here
<source>:18:20: internal compiler error: in parameter_mapping_equivalent_p, at
cp/constraint.cc:615
   18 |     Class<Enum::A>{};
      |                    ^
0x236fd8e internal_error(char const*, ...)
        ???:0
0xaa5338 fancy_abort(char const*, int, char const*)
        ???:0
0xb21e30 sat_hasher::equal(sat_entry*, sat_entry*)
        ???:0
0xb22b7c hash_table<sat_hasher, false,
xcallocator>::find_slot_with_hash(sat_entry* const&, unsigned int,
insert_option)
        ???:0
0xb1c8b3 satisfaction_cache::satisfaction_cache(tree_node*, tree_node*,
sat_info)
        ???:0
0xb21202 constraints_satisfied_p(tree_node*, tree_node*)
        ???:0
0xad1f2a build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, tree_node*, int, tree_node**, int)
        ???:0
0xad23d7 build_special_member_call(tree_node*, tree_node*, vec<tree_node*,
va_gc, vl_embed>**, tree_node*, int, int)
        ???:0
0xad9d70 perform_direct_initialization_if_possible(tree_node*, tree_node*,
bool, int)
        ???:0
0xd4c672 cp_build_c_cast(unsigned int, tree_node*, tree_node*, int)
        ???:0
0xd554b6 build_functional_cast(unsigned int, tree_node*, tree_node*, int)
        ???:0
0xcf72ef finish_compound_literal(tree_node*, tree_node*, int, fcl_t)
        ???:0
0xc80597 c_parse_file()
        ???:0
0xdbdde9 c_common_parse_file()
        ???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
```