[PATCH] Three regex speedups, one of which is actually a bugfix

[Paolo Bonzini]

> And one more hint: a lot of the functions have parameters only because
> they need to be passed down to other functions.  This has been somewhat
> reduced but it potentially can be done better.  If __thread is available
> we can use thread-local static variables.

What TLS model do they use?  Is any optimization possible since they are static?
Unless it is local-exec I doubt it is worth it.

Paolo