[Patch] Fix wrong backup variable initialization in regex

[Paolo Carlini]

On 10/03/2013 07:33 PM, Tim Shen wrote:
> Tested under -m32, -m64, however didn't do a  bootstrap. Is that OK?
Seems trivial enough, Ok.

Thanks,
Paolo

PS: I suppose isn't easy to prepare a testcase which would exercise 
those lines?