op_comp

[Reini Urban]

finish op_comp to fill in values.

code blocks are extracted like this:

/a(?{$a=2;$b=3;($b)=$a})b/ =>
expr: 'a' + getvars + '(?{$a=2;$b=3;($b)=$a})' + 'b'

currently we only compile the first 'a', not the other patterns

[Reini Urban]

Done with 262567b