[Bug c++/107152] New: ICE: Segmentation fault (in get_shorthand_constraints)

[Bug c++/107152] New: ICE: Segmentation fault (in get_shorthand_constraints)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107152

            Bug ID: 107152
           Summary: ICE: Segmentation fault (in get_shorthand_constraints)
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: error-recovery, ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

g++ 13.0.0 20220925 snapshot (g:77bbf69d2981dafc2ef3e59bfbefb645d88bab9d) ICEs
when compiling the following testcase, reduced from
test/Modules/template-function-specialization.cpp from the clang 15.0.1 test
suite:

export template <>
void foo4<int>() {
}

% g++-13.0.0 -std=c++20 -w -c rnforwjm.cpp
rnforwjm.cpp:1:18: error: invalid explicit specialization before '>' token
    1 | export template <>
      |                  ^
rnforwjm.cpp:1:18: internal compiler error: Segmentation fault
0x11dc98f crash_signal
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/toplev.cc:314
0x9c7cd6 tree_check(tree_node*, char const*, int, char const*, tree_code)
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/tree.h:3519
0x9c7cd6 get_shorthand_constraints(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/constraint.cc:1558
0xb2de2b cp_parser_explicit_template_declaration
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/parser.cc:31825
0xb3094a cp_parser_declaration
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/parser.cc:15038
0xb31509 cp_parser_toplevel_declaration
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/parser.cc:15130
0xb31509 cp_parser_translation_unit
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/parser.cc:5068
0xb31509 c_parse_file()
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/cp/parser.cc:48606
0xc6e3a1 c_common_parse_file()
       
/var/tmp/portage/sys-devel/gcc-13.0.0_p20220925/work/gcc-13-20220925/gcc/c-family/c-opts.cc:1255