patch 8.2.1269: language and locale code spread out

Problem:    Language and locale code spread out.
Solution:   Move relevant code to src/locale.c. (Yegappan Lakshmanan,
            closes #6509)
diff --git a/src/proto/locale.pro b/src/proto/locale.pro
new file mode 100644
index 0000000..151e68a
--- /dev/null
+++ b/src/proto/locale.pro
@@ -0,0 +1,9 @@
+/* locale.c */
+char_u *get_mess_lang(void);
+void set_lang_var(void);
+void init_locale(void);
+void ex_language(exarg_T *eap);
+void free_locales(void);
+char_u *get_lang_arg(expand_T *xp, int idx);
+char_u *get_locales(expand_T *xp, int idx);
+/* vim: set ft=c : */