Reintroducing parser changes to cause compile-time errors when trying to reinitialize a final field…

tests/language/final_attempt_reinitialization_test.dart

+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class Foo {
+  Foo(this.x); //# 01: compile-time error
+  final int x = 42; //# 01: compile-time error
+}
+
+class CoffeeShop {
+  final String shopName = "Coffee Lab"; //# 02: compile-time error
+  CoffeeShop.name(String shopName) //# 02: compile-time error
+      : this.shopName = shopName; //# 02: compile-time error
+}
+
+void main() {
+  Foo f = new Foo(10); //# 01: compile-time error
+  CoffeeShop presidentialCoffee = //# 02: compile-time error
+      new CoffeeShop.name("Covfefe Lab"); //# 02: compile-time error
+}