[Perl/perl5] 0cafd0: Fix perlop.pod about isa operator's precedence

[Paul Evans via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 0cafd09c4306be6a918d02a4554bc5b8a599a05a
      
https://github.com/Perl/perl5/commit/0cafd09c4306be6a918d02a4554bc5b8a599a05a
  Author: Paul "LeoNerd" Evans <leon...@leonerd.org.uk>
  Date:   2021-05-04 (Tue, 04 May 2021)

  Changed paths:
    M pod/perlop.pod

  Log Message:
  -----------
  Fix perlop.pod about isa operator's precedence