[Perl/perl5] f8312f: gh19010: add NOT_REACHED

[Hugo van der Sanden via perl5-changes]

  Branch: refs/heads/hv/gh19010
  Home:   https://github.com/Perl/perl5
  Commit: f8312f207e8c5c01f7a74e6f4adab0ee95c1a336
      
https://github.com/Perl/perl5/commit/f8312f207e8c5c01f7a74e6f4adab0ee95c1a336
  Author: Hugo van der Sanden <h...@crypt.org>
  Date:   2022-03-04 (Fri, 04 Mar 2022)

  Changed paths:
    M numeric.c

  Log Message:
  -----------
  gh19010: add NOT_REACHED