[Bug libgomp/126019] New: ICE when parsing #pragma GCC diagnostic inside [[omp::directive(begin assumes ...)]]

[s.kimura.h41104 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126019

            Bug ID: 126019
           Summary: ICE when parsing #pragma GCC diagnostic inside
                    [[omp::directive(begin assumes ...)]]
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: s.kimura.h41104 at gmail dot com
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

Compiler Explorer: https://godbolt.org/z/fh395KqaK

Reproducer:
```
[[omp::directive(begin assumes
#pragma GCC diagnostic
                 )]];
```

Backtrace:
<source>:2:23: internal compiler error: in cp_parser_declaration, at
cp/parser.cc:17567
    2 | #pragma GCC diagnostic
      |                       ^
0x2a1f758 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
        ???:0
0x2a1439b internal_error(char const*, ...)
        ???:0
0xb36178 fancy_abort(char const*, int, char const*)
        ???:0
0xd89ca3 c_parse_file()
        ???:0
0xf1a489 c_common_parse_file()
        ???:0

This ICE goes back to gcc-13:
https://godbolt.org/z/sa34P8K6Y