[perl #72590] Panic if 'use strict' and forget 'my'

[perl #72590] Panic if 'use strict' and forget 'my'

That bug happens when we detect a compilation error in the statement
being parsed, and when the continuation of the parsing of that same
statement needs to load the file unicore/Name.pl via charnames.pm.
In that case perl gets confused, fails to parse Name.pl because
the parser is already in error, and also fails to properly rewind
to a normal error-reporting state.

This patch does not attempt to fix the whole error-reporting process;
instead, it simply prevents perl from trying to load charnames if it has
already recorded a parse error. So, in a way, it hides the bug under
the carpet. However, this is a safe fix, suitable for a code-freeze
stage.