vm.c (prepare_missing): add receiver's class in superclass calls

src/vm.c

@@ -615,7 +615,7 @@ prepare_missing(mrb_state *mrb, mrb_callinfo *ci, mrb_value recv, mrb_sym mid, m
 
   if (mrb_func_basic_p(mrb, recv, missing, mrb_obj_missing)) {
   method_missing:
-    if (super) mrb_no_method_error(mrb, mid, args, "no superclass method '%n'", mid);
+    if (super) mrb_no_method_error(mrb, mid, args, "no superclass method '%n' for %T", mid, recv);
     else mrb_method_missing(mrb, mid, recv, args);
     /* not reached */
   }

test/t/kernel.rb

@@ -346,7 +346,7 @@ assert('Kernel#method_missing', '15.3.1.3.30') do
     end
   end
   no_super_test = NoSuperMethodTestClass.new
-  msg = "no superclass method 'no_super_method_named_this'"
+  msg = "no superclass method 'no_super_method_named_this' for NoSuperMethodTestClass"
   assert_raise_with_message(NoMethodError, msg) do
     no_super_test.no_super_method_named_this
   end