Fix compile errors, code review feedback, and add basic libc test suite.

@@ -97,7 +97,8 @@
 extern struct locdata   __posix_monetary_locdata;
 extern struct locdata   __posix_messages_locdata;
 extern struct locdata   __posix_time_locdata;
 extern struct locdata   __posix_ctype_locdata;
 extern struct locdata   __posix_collate_locdata;
+extern locale_t ___global_locale; 
 
 #endif  /* _LOCALEIMPL_H_ */