[PATCH] More helpful result of NOT_REACHED assertion

Before:
  perl5.31.2: op.c:1921: Perl_scalar: Assertion `0' failed.

"0" isn't very descriptive.

After:
  perl5.31.2: op.c:1921: Perl_scalar: Assertion `!"UNREACHABLE"' failed.

A little more helpful as it immediately reminds you this is an
unreachable statement that was reached.

-- 
Paul "LeoNerd" Evans

leonerd@leonerd.org.uk      |  https://metacpan.org/author/PEVANS
http://www.leonerd.org.uk/  |  https://www.tindie.com/stores/leonerd/

• [PATCH] More helpful result of NOT_REACHED assertion by Paul "LeoNerd" Evans