libstdc++ ctype & os support for Darwin

[Loren James Rittle]

Geoffrey Keating <gkeating@apple.com> wrote:
>- I got testcase failures.  It turned out they were due to code in
>  locale/generic/ctype_members.cc like
>
>    const size_t __bitmasksize = 15;
>    for (size_t __bitcur = 0; __bitcur <= __bitmasksize; ++__bitcur)
>      if (__m & _M_bit[__bitcur]
>         && iswctype(__c, _M_wmask[__bitcur]))
>
>  which doesn't work on Darwin (or, probably FreeBSD), since they use
>  high bits from a 32-bit word.
 
Thank you for this reference.  I will take a look at this to see
if it fixes any outstanding failures with mainline on FreeBSD (at 49
in libstdc++-v3, last I checked).
 
Regards,
Loren