Fix incorrect syntax in constant evaluation test.

pkg/analyzer/test/generated/all_the_rest.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.all_the_rest_test;
 
 import 'dart:collection';
@@ skipping 4025 matching lines @@
 
   void
       test_instanceCreationExpression_fieldFormalParameter_unnamedOptionalWithoutDefault() {
     _checkInstanceCreationOptionalParams(true, false, false);
   }
 
   void test_instanceCreationExpression_implicitSuper() {
     CompilationUnit compilationUnit = resolveSource(r'''
 const foo = const B(4);
 class A {
-  const A() : x(3);
+  const A() : x = 3;
   final int x;
 }
 class B extends A {
   const B(this.y);
   final int y;
 }''');
     EvaluationResultImpl result =
         _evaluateInstanceCreationExpression(compilationUnit, "foo");
     Map<String, DartObjectImpl> fields = _assertType(result, "B");
     expect(fields, hasLength(2));
@@ skipping 7006 matching lines @@
     Source scriptSource = externalScript.scriptSource;
     if (_expectedExternalScriptName == null) {
       expect(scriptSource, isNull, reason: "script $scriptIndex");
     } else {
       expect(scriptSource, isNotNull, reason: "script $scriptIndex");
       String actualExternalScriptName = scriptSource.shortName;
       expect(actualExternalScriptName, _expectedExternalScriptName, reason: "script $scriptIndex");
     }
   }
 }