Actually fix parsing for options with optional values.
This state runs spectests again.

Apparently the TOP rule in Perl6::CommandLine::Parser was
bogus, and it didn't parse the case "only one argument",
which resulted in not being able to rune make spectest.
Bring delimited options into Perl 6 land in %*OPTS.

This also included a few bug fixes, spectest runs and
is clean.