[Patch] Optimize _BFSExecutor in regex

[Paolo Carlini]

On 10/07/2013 12:43 AM, Tim Shen wrote:
> Here's a simple piece of code
> https://gist.github.com/innocentim/6849759 the reveals _BFSExecutor's
> inefficiency.
... which we want in testsuite/performance/28_regex!

Thanks!
Paolo.