[modules] Don't unnecessarily keep function alive after evaluation.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 6ab515c879cfccff67eddb4bf10c113e17e1efdc..aed4af089b7c5b1eeb79194fa1622feba4c0daee 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -1922,7 +1922,7 @@ MaybeLocal<Value> Module::Evaluate(Local<Context> context) {
 
   i::Handle<i::Module> self = Utils::OpenHandle(this);
   // It's an API error to call Evaluate before Instantiate.
-  CHECK(self->code()->IsJSFunction());
+  CHECK(self->instantiated());
 
   Local<Value> result;
   has_pending_exception = !ToLocal(i::Module::Evaluate(self), &result);