(st_locale_insensitive_strncasecmp): Renamed from st_strncasecmp.

* include/ruby/st.h: Follow above changes.

* include/ruby/ruby.h: Ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42012 b2dd03c8-39d4-4d8f-98ff-823fe69b080e