Fix inline cache incoherency for ME resolved through VM_METHOD_TYPE_R…

…EFINED

Previously, we didn't invalidate the method entry wrapped by
VM_METHOD_TYPE_REFINED method entries which could cause calls to
land in the wrong method like in the included test.

Fixup: cfd7729
See-also: e201b81

test/ruby/test_refinement.rb

@@ -2650,6 +2650,28 @@ def to_s = :R
     end;
   end
 
+  def test_inline_cache_invalidation
+    klass = Class.new do
+      def cached_foo_callsite = foo
+
+      def foo = :v1
+
+      host = self
+      @refinement = Module.new do
+        refine(host) do
+          def foo = :unused
+        end
+      end
+    end
+
+    obj = klass.new
+    obj.cached_foo_callsite # prime cache
+    klass.class_eval do
+      def foo = :v2 # invalidate
+    end
+    assert_equal(:v2, obj.cached_foo_callsite)
+  end
+
   private
 
   def eval_using(mod, s)

vm_method.c

@@ -240,6 +240,13 @@ clear_method_cache_by_id_in_class(VALUE klass, ID mid)
                 vm_cme_invalidate((rb_callable_method_entry_t *)cme);
                 RB_DEBUG_COUNTER_INC(cc_invalidate_tree_cme);
 
+                // In case of refinement ME, also invalidate the wrapped ME that
+                // could be cached at some callsite and is unreachable from any
+                // RCLASS_CC_TBL.
+                if (cme->def->type == VM_METHOD_TYPE_REFINED && cme->def->body.refined.orig_me) {
+                    vm_cme_invalidate((rb_callable_method_entry_t *)cme->def->body.refined.orig_me);
+                }
+
                 if (cme->def->iseq_overload) {
                     rb_callable_method_entry_t *monly_cme = (rb_callable_method_entry_t *)lookup_overloaded_cme(cme);
                     if (monly_cme) {