[Bug c++/91644] New: [C++20] constinit segfaults inside templated functions

[pexu@gcc-bugzilla.mail.kapsi.fi]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91644

            Bug ID: 91644
           Summary: [C++20] constinit segfaults inside templated functions
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pexu@gcc-bugzilla.mail.kapsi.fi
  Target Milestone: ---

Created attachment 46804
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46804&action=edit
constinit test cases

Hi.

Reading P1143R2 my understanding is that the constinit initialization should be
also possible inside a function scope.  If I'm mistaken, it should be
diagnosted and rejected.  Nonetheless, it currently segfaults the compiler, if
the function happens to be templated, so it needs some adjustment anyway:

template < typename T >
static void function() {
  static __constinit auto value = 0;
}

Attached a few test cases.