Tweak _generic_/ctype_members.cc (do_is(mask, wchar_t) for iswspace

[Paolo Carlini]

Hi again,

>Is it it worthwhile to allow same "common case" tweak for generic?
>It works on cygwin and mingw32. But, to be honest, I have not really
>tried to measure a performance effect on those two targets.
>
>2007-06-25  Danny Smith   <dannysmith@users.sourceforege.net>
>
>	* config/locale/gnu/ctype_members.cc (do_is(mask, wchar_t))
>	[_GLIBCXX_CTYPE_SPACE_BIT]: Speed-up for the common case of
>	mask == ctype_base::space,
>	* config/os/mingw32/ctype_base.h: (_GLIBCXX_CTYPE_SPACE_BIT):
>Define
>	* config/os/newlib/ctype_base.h (_GLIBCXX_CTYPE_SPACE_BIT):
>Define.
>  
>
for now, I would just go ahead with your patch. A minor nit: for 
defining _GLIBCXX_CTYPE_SPACE_BIT, os_defines.h seems more suited.

Paolo.