[Bug c++/105541] New: ICE: Segmentation fault when template lambda in requires-clause

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105541

            Bug ID: 105541
           Summary: ICE: Segmentation fault when template lambda in
                    requires-clause
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

template<class>
constexpr bool is_hello = false;

template <typename T>
  requires (!is_hello<T>)
class Hello;

template <typename T>
  requires (!is_hello<T>)
class Hello {};

static_assert(requires { []<Hello<int>>{}; });

https://godbolt.org/z/rTM5chYf3

GCC-11 rejects this valid syntax, and GCC-12 emits ICE.