store ctx objects in hidden global variables

Author: Asmod4n

include/mruby/msgpack.h

@@ -17,7 +17,6 @@ MRB_API void mrb_msgpack_register_pack_type_value(mrb_state *mrb, int8_t type, m
 MRB_API void mrb_msgpack_register_unpack_type_value(mrb_state *mrb, int8_t type, mrb_value proc);
 MRB_API void mrb_msgpack_register_pack_type_cfunc(mrb_state *mrb, int8_t type, struct RClass *klass, mrb_func_t cfunc, mrb_int argc, const mrb_value *argv);
 MRB_API void mrb_msgpack_register_unpack_type_cfunc(mrb_state *mrb, int8_t type, mrb_func_t cfunc, mrb_int argc, const mrb_value *argv);
-MRB_API void mrb_msgpack_teardown(mrb_state *mrb);
 MRB_API void mrb_msgpack_set_symbol_strategy(mrb_state *mrb, mrb_sym which, int8_t ext_type);
 MRB_API mrb_value mrb_msgpack_get_symbol_strategy(mrb_state *mrb);