localeinit.c: split

* localeinit.c (rb_locale_charmap, Init_enc_set_filesystem_encoding):
  move from encoding.c.
* miniinit.c (rb_locale_charmap, Init_enc_set_filesystem_encoding):
  define miniruby specific functions only.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41973 b2dd03c8-39d4-4d8f-98ff-823fe69b080e