(_CTYPE_GEORGIAN_PS_255): Define.
(_CTYPE_PT154_128_254): Define.
(_CTYPE_PT154_255): Define.
(__ctype_cp): Add array members for above ctype definitions.
* libc/locale/locale.c (loadlocale): Make TIS-620 charset name
available for all targets. Add guards for setting the conversion
function pointers. Add support for GEORGIAN-PS and PT154 charsets.
Change documentation to reflect current behaviour more closely.
* libc/locale/nl_langinfo.c (nl_langinfo): On Cygwin, translate
"CP101" to "GEORGIAN-PS" and "CP102" to "PT154".
* libc/stdlib/sb_charsets.c (__cp_conv): Add conversion arrays
for GEORGIAN-PS and PT154.
(__cp_index): Map invalid Windows codepage number 101 to
GEORGIAN-PS conversion array, 102 to PT154 conversion array.