* configure.host (darwin*): Set os_include_dir to a separate directory
for Darwin.
* acinclude.m4 (GLIBCXX_ENABLE_CLOCALE): Add a new C locale kind,
'darwin'.
* config/locale/darwin/ctype_members.cc: New.
* config/os/bsd/darwin/ctype_base.h: New.
* config/os/bsd/darwin/ctype_inline.h: New.
* config/os/bsd/darwin/ctype_noninline.h: New.
* config/os/bsd/darwin/os_defines.h: New.
From-SVN: r89874