Improve locale and language environment setting at startup
* lisp/international/mule-cmds.el (locale-language-names): Add more locales and their language environments. (set-locale-environment): Use w32-multibyte-code-page, if non-zero, as locale-coding-system. (Bug#34684) * src/w32fns.c (globals_of_w32fns) <w32-multibyte-code-page>: New variable. * etc/NEWS: Mention w32-multibyte-code-page.