Arrow functions prototype property should not be lazy instantiated (#3251)

This patch fixes #3250

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

jerry-core/ecma/operations/ecma-function-object.c

@@ -1260,7 +1260,8 @@ ecma_op_function_try_to_lazy_instantiate_property (ecma_object_t *object_p, /**<
 {
   JERRY_ASSERT (!ecma_get_object_is_builtin (object_p));
 
-  if (ecma_compare_ecma_string_to_magic_id (property_name_p, LIT_MAGIC_STRING_PROTOTYPE))
+  if (ecma_compare_ecma_string_to_magic_id (property_name_p, LIT_MAGIC_STRING_PROTOTYPE)
+      && ecma_get_object_type (object_p) == ECMA_OBJECT_TYPE_FUNCTION)
   {
     return ecma_op_lazy_instantiate_prototype_object (object_p);
   }

tests/jerry/es2015/regression-test-issue-3250.js

@@ -0,0 +1,16 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var arrowFn = () => { };
+assert (arrowFn.prototype === undefined);