* autoload (noload): Avoid clobbering bx register.

* autoload (noload): Avoid clobbering bx register.
* environ.cc (codepage_init): Use case insensitive match.
* fhandler_console.cc (cp_get_internal): Delete.
(con_to_str): Use get_cp to derive code page.
(str_to_con): Ditto.
* miscfuncs.cc (get_cp): New function.
(sys_wcstombs): New function.  Converted from macro.
(sys_mbstowcs): Ditto.
* winsup.h: Reflect above changes.