[Patch] Fix undefined behaviors in regex

[Tim Shen]

It's detected by `clang++ -g -std=c++11 -fsanitize=undefined` but not
detected by g++ with flags `g++ -g -std=c++11 -fsanitize=undefined
-lpthread`. Am I on the right way?

-m32 and -m64 tested :)

Thanks!


-- 
Tim Shen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: a.patch
Type: application/octet-stream
Size: 1332 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20131016/f16894e9/attachment.obj>