regcomp.c - make sure conditional match (GROUPP) is not broken by CURLYM

[demerphq]

This disables the CURLY->CURLYM optimization when the contents contains a GROUPP.

This PR also includes a prior commit which fixes this a different, less efficient way, and then corrects that to a better way afterwards.

See #7754

[demerphq]

CURLYM fakes an OPEN/CLOSE paren, and was deferring updating its close paren data until after it finished looping. This meant that tests against the capture buffer would not work. Changed it to close the parens each time. An alternative solution would be to exclude cases containing conditional logic from the CURLYX->CURLYM conversion, just like EVAL is excluded.

[demerphq]

I will merge this tomorrow unless there are objections.

[khwilliamson]

I've never understood this area of the code very well, but it looks plausible to me