* libc/locale/locale.c (_setlocale_r): New implementation based on

	* libc/locale/locale.c (_setlocale_r): New implementation based on
	FreeBSD's setlocale.
	(currentlocale): New helper function.
	(loadlocale): Ditto.
	(__locale_charset): New function.
	(__locale_msgcharset): Rename from __locale_charset.
	* libc/ctype/local.h (__lc_ctype): Remove declaration.
	(__locale_charset): Declare.
	* libc/ctype/iswalpha.c (iswalpha): Call __locale_charset instead of
	using __lc_ctype directly.  Only compare against the charset alone.
	* libc/ctype/iswblank.c (iswblank): Ditto.
	* libc/ctype/iswcntrl.c (iswcntrl): Ditto.
	* libc/ctype/iswprint.c (iswprint): Ditto.
	* libc/ctype/iswpunct.c (iswpunct): Ditto.
	* libc/ctype/iswspace.c (iswspace): Ditto.
	* libc/ctype/towlower.c (towlower): Ditto.
	* libc/ctype/towupper.c (towupper): Ditto.
	* libc/stdlib/mbtowc_r.c (_mbtowc_r): Ditto.
	* libc/stdlib/wctomb_r.c (_wctomb_r): Ditto.
	* libc/sys/linux/intl/loadmsgcat.c (_nl_init_domain_conv): Call
	__locale_msgcharset instead of __locale_charset.