Update forcing of lexical environment creation for functions. (#3683)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

tests/jerry/es2015/arrow-eval.js

@@ -0,0 +1,41 @@
+/* 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.
+ */
+
+let a = 4
+
+var f = () => {
+  eval("var a = 5")
+  assert(a === 5)
+}
+f()
+
+assert(a === 4)
+
+function g() {
+  eval("var b = 6")
+
+  assert(b === 6)
+
+  var h = () => delete b
+  h()
+
+  try {
+    b
+    assert(false)
+  } catch (e) {
+    assert(e instanceof ReferenceError)
+  }
+}
+g()