Revert "Add MRB_IMPROVE_META_PROGRAMMING configuration"

This reverts commit 1997fcf98f.
It became the default behavior.

include/mrbconf.h

@@ -110,9 +110,6 @@
 /* fixed size state atexit stack */
 //#define MRB_FIXED_STATE_ATEXIT_STACK
 
-/* improve meta programming support */
-//#define MRB_IMPROVE_META_PROGRAMMING
-
 /* -DMRB_DISABLE_XXXX to drop following features */
 //#define MRB_DISABLE_STDIO /* use of stdio */
 

src/variable.c

@@ -344,9 +344,7 @@ mrb_iv_get(mrb_state *mrb, mrb_value obj, mrb_sym sym)
   return mrb_nil_value();
 }
 
-#ifdef MRB_IMPROVE_META_PROGRAMMING
 static inline void assign_class_name(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v);
-#endif
 
 MRB_API void
 mrb_obj_iv_set(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
@@ -356,9 +354,7 @@ mrb_obj_iv_set(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
   if (MRB_FROZEN_P(obj)) {
     mrb_raisef(mrb, E_FROZEN_ERROR, "can't modify frozen %S", mrb_obj_value(obj));
   }
-#ifdef MRB_IMPROVE_META_PROGRAMMING
   assign_class_name(mrb, obj, sym, v);
-#endif
   if (!obj->iv) {
     obj->iv = iv_new(mrb);
   }
@@ -367,7 +363,6 @@ mrb_obj_iv_set(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
   mrb_write_barrier(mrb, (struct RBasic*)obj);
 }
 
-#ifdef MRB_IMPROVE_META_PROGRAMMING
 static inline mrb_bool
 is_namespace(enum mrb_vtype tt)
 {
@@ -399,7 +394,6 @@ assign_class_name(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
     }
   }
 }
-#endif
 
 MRB_API void
 mrb_iv_set(mrb_state *mrb, mrb_value obj, mrb_sym sym, mrb_value v)
@@ -1110,14 +1104,10 @@ mrb_class_find_path(mrb_state *mrb, struct RClass *c)
 
   str = mrb_sym2name_len(mrb, name, &len);
   mrb_str_cat(mrb, path, str, len);
-#ifdef MRB_IMPROVE_META_PROGRAMMING
   if (RSTRING_PTR(path)[0] != '#') {
-#endif
     iv_del(mrb, c->iv, mrb_intern_lit(mrb, "__outer__"), NULL);
     iv_put(mrb, c->iv, mrb_intern_lit(mrb, "__classname__"), path);
     mrb_field_write_barrier_value(mrb, (struct RBasic*)c, path);
-#ifdef MRB_IMPROVE_META_PROGRAMMING
   }
-#endif
   return path;
 }