[Bug c++/81899] New: [8 Regression] ICE: Segmentation fault

["trippels at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81899

            Bug ID: 81899
           Summary: [8 Regression] ICE: Segmentation fault
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---

% cat auto_switch_lexerstate.ii
template <int> struct bool_;
template <typename = bool_<0>> struct token;
template <typename,
          template <typename, typename, typename, typename> class FunctorData,
          typename>
struct functor {
  friend FunctorData<int, int, int, int>;
  void foo();
};
template <typename, typename, typename, typename> struct data;
template<> void functor<token<>, data, bool_<0>>::foo();

 % g++ -c auto_switch_lexerstate.ii
auto_switch_lexerstate.ii: In instantiation of ‘struct functor<token<>, data,
bool_<0> >’:
auto_switch_lexerstate.ii:11:49:   required from here
auto_switch_lexerstate.ii:6:16: internal compiler error: Segmentation fault
 struct functor {
                ^
0x10ba3023 crash_signal
        ../../gcc/gcc/toplev.c:341
0x1044d53c instantiate_class_template_1
        ../../gcc/gcc/cp/pt.c:10727
0x1044d53c instantiate_class_template(tree_node*)
        ../../gcc/gcc/cp/pt.c:10892
0x104c1ceb complete_type(tree_node*)
        ../../gcc/gcc/cp/typeck.c:136
0x103a69e7 cp_parser_nested_name_specifier_opt
        ../../gcc/gcc/cp/parser.c:6269
0x103a7833 cp_parser_nested_name_specifier
        ../../gcc/gcc/cp/parser.c:6332
0x103a794b cp_parser_ptr_operator
        ../../gcc/gcc/cp/parser.c:20451
0x103aac0b cp_parser_declarator
        ../../gcc/gcc/cp/parser.c:19771
0x103bf7ab cp_parser_init_declarator
        ../../gcc/gcc/cp/parser.c:19335
0x103c0b53 cp_parser_single_declaration
        ../../gcc/gcc/cp/parser.c:27053
0x103c1d73 cp_parser_explicit_specialization
        ../../gcc/gcc/cp/parser.c:16619
0x103ce603 cp_parser_declaration
        ../../gcc/gcc/cp/parser.c:12720
0x103cc6ef cp_parser_declaration_seq_opt
        ../../gcc/gcc/cp/parser.c:12650
0x103ccaeb cp_parser_translation_unit
        ../../gcc/gcc/cp/parser.c:4387
0x103ccaeb c_parse_file()
        ../../gcc/gcc/cp/parser.c:38894
0x10563ee7 c_common_parse_file()
        ../../gcc/gcc/c-family/c-opts.c:1106