Optimize regex matching for finding non-global matches

[LinqLover]

matchesRegex: '.*...' should be as fast as RxMatcher>>search:, but is currently significantly slower:

longString := String new: 10000 withAll: $x.
longString matchesRegex: '.*y'.
'y' asRegex search: longString.

Can RxMatchOptimizer handle this?

Related issues:

• search: is pretty inefficient, maybe it could utilize something like findSubstring:
• analogously, in the other direction, lookbehind matching is very inefficient and could benefit from a "backwards matching" mode ... so many construction sites :-)