Remove `MRB_API` from `mrb_instance_new`.

include/mruby.h

@@ -570,8 +570,6 @@ MRB_INLINE mrb_value mrb_class_new_instance(mrb_state *mrb, mrb_int argc, const
   return mrb_obj_new(mrb,c,argc,argv);
 }
 
-MRB_API mrb_value mrb_instance_new(mrb_state *mrb, mrb_value cv);
-
 /**
  * Creates a new instance of Class, Class.
  *

include/mruby/class.h

@@ -85,6 +85,7 @@ MRB_API mrb_method_t mrb_method_search_vm(mrb_state*, struct RClass**, mrb_sym);
 MRB_API mrb_method_t mrb_method_search(mrb_state*, struct RClass*, mrb_sym);
 
 MRB_API struct RClass* mrb_class_real(struct RClass* cl);
+mrb_value mrb_instance_new(mrb_state *mrb, mrb_value cv);
 
 void mrb_class_name_class(mrb_state*, struct RClass*, struct RClass*, mrb_sym);
 mrb_value mrb_class_find_path(mrb_state*, struct RClass*);

src/class.c

@@ -1498,7 +1498,7 @@ mrb_instance_alloc(mrb_state *mrb, mrb_value cv)
  *
  */
 
-MRB_API mrb_value
+mrb_value
 mrb_instance_new(mrb_state *mrb, mrb_value cv)
 {
   mrb_value obj, blk;