[Bug c++/110056] New: ICE on trying to generate header unit for 'execution'

["saifi.khan at nishan dot io" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110056

            Bug ID: 110056
           Summary: ICE on trying to generate header unit for 'execution'
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: saifi.khan at nishan dot io
  Target Milestone: ---

ENV
AMD64 x86_64 64-bit
Linux 6.3.5
glibc 2.37-3
gcc version 14.0.0 20230531 (experimental)

CMD
g++  -std=c++23 -g3 -fmodules-ts -fmodule-only -c -x c++-system-header 
execution

OUTPUT
In file included from
/opt/gcc/include/c++/14.0.0/pstl/parallel_backend_serial.h:16,
                 from /opt/gcc/include/c++/14.0.0/pstl/parallel_backend.h:14,
                 from /opt/gcc/include/c++/14.0.0/pstl/algorithm_impl.h:22,
                 from
/opt/gcc/include/c++/14.0.0/pstl/glue_execution_defs.h:50,
                 from /opt/gcc/include/c++/14.0.0/execution:34:
/opt/gcc/include/c++/14.0.0/numeric: In function ‘constexpr
std::common_type_t<_Tp1, _Tp2> std::lcm(_Mn, _Nn)’:
/opt/gcc/include/c++/14.0.0/numeric:193:13: internal compiler error: in
lookup_mark, at cp/tree.cc:2467
  193 |         if (__is_constant_evaluated())
      |             ^~~~~~~~~~~~~~~~~~~~~~~
0x7acd8c lookup_mark(tree_node*, bool)
        /opt/gcc/src/gcc/cp/tree.cc:2467
0xb61c7c name_lookup::dedup(bool)
        /opt/gcc/src/gcc/cp/name-lookup.cc:481
0xb61c7c name_lookup::dedup(bool)
        /opt/gcc/src/gcc/cp/name-lookup.cc:476
0xb61c7c name_lookup::search_namespace_only(tree_node*)
        /opt/gcc/src/gcc/cp/name-lookup.cc:949
0xb631cb name_lookup::search_unqualified(tree_node*, cp_binding_level*)
        /opt/gcc/src/gcc/cp/name-lookup.cc:1142
0xb67a37 lookup_name(tree_node*, LOOK_where, LOOK_want)
        /opt/gcc/src/gcc/cp/name-lookup.cc:7564
0xb78d3a lookup_name(tree_node*, LOOK_want)
        /opt/gcc/src/gcc/cp/name-lookup.h:402
0xb78d3a cp_parser_lookup_name
        /opt/gcc/src/gcc/cp/parser.cc:31412
0xbaad49 cp_parser_class_name
        /opt/gcc/src/gcc/cp/parser.cc:26003
0xbab03c cp_parser_type_name
        /opt/gcc/src/gcc/cp/parser.cc:20333
0xbbbe77 cp_parser_simple_type_specifier
        /opt/gcc/src/gcc/cp/parser.cc:20024
0xb91805 cp_parser_type_specifier
        /opt/gcc/src/gcc/cp/parser.cc:19614
0xb935d4 cp_parser_decl_specifier_seq
        /opt/gcc/src/gcc/cp/parser.cc:16089
0xbb4fb1 cp_parser_condition
        /opt/gcc/src/gcc/cp/parser.cc:13486
0xbc5494 cp_parser_selection_statement
        /opt/gcc/src/gcc/cp/parser.cc:13243
0xb9741b cp_parser_statement
        /opt/gcc/src/gcc/cp/parser.cc:12410
0xbc4a91 cp_parser_implicitly_scoped_statement
        /opt/gcc/src/gcc/cp/parser.cc:14578
0xbc5714 cp_parser_selection_statement
        /opt/gcc/src/gcc/cp/parser.cc:13276
0xb9741b cp_parser_statement
        /opt/gcc/src/gcc/cp/parser.cc:12410
0xb9808e cp_parser_statement_seq_opt
        /opt/gcc/src/gcc/cp/parser.cc:13000