[Patch] Let ordinary escaping in POSIX regex be valid

[Tim Shen]

POSIX ERE says that escaping an ordinary char, say R"\n" is not
permitted, because 'n' is not a special char. However, they also say
that : "Implementations are permitted to extend the language to allow
these. Conforming applications cannot use such constructs."

So let's support it not to make users surprised.

Booted and tested under -m32 and -m64

Thanks!


-- 
Tim Shen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: a.patch
Type: application/octet-stream
Size: 1349 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20130927/e2eca653/attachment.obj>