Implement visitCascade/visitCascadeReceiver in inferrer_visitor.dart

tests/compiler/dart2js/simple_inferrer_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:expect/expect.dart';
 import
     '../../../sdk/lib/_internal/compiler/implementation/types/types.dart'
     show TypeMask;
 
 import 'compiler_helper.dart';
@@ skipping 386 matching lines @@
   returnInt2() => new A().myField += 4;
   returnInt3() => ++new A()[0];
   returnInt4() => new A()[0] += 42;
   returnInt5() => ++super.myField;
   returnInt6() => super.myField += 4;
   returnInt7() => ++super[0];
   returnInt8() => super[0] += 54;
   returnInt9() => super.myField;
 }
 
+testCascade1() {
+  return [1, 2, 3]..add(4)..add(5);
+}
+
+testCascade2() {
+  return new CascadeHelper()
+      ..a = "hello"
+      ..b = 42
+      ..i += 1;
+}
+
+class CascadeHelper {
+  var a, b;
+  var i = 0;
+}
+
 main() {
   // Ensure a function class is being instantiated.
   () => 42;
   returnNum1(true);
   returnNum2(true);
   returnInt1(true);
   returnInt2(true);
   returnInt3(true);
   returnInt4();
   returnDouble(true);
@@ skipping 54 matching lines @@
          ..returnInt4()
          ..returnInt5()
          ..returnInt6()
          ..returnInt7()
          ..returnInt8()
          ..returnInt9();
   testReturnElementOfConstList1();
   testReturnElementOfConstList2();
   testReturnItselfOrInt(topLevelGetter());
   testReturnInvokeDynamicGetter();
+  testCascade1();
+  testCascade2();
 }
 """;
 
 void main() {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
   compiler.runCompiler(uri);
   var typesTask = compiler.typesTask;
   var typesInferrer = typesTask.typesInferrer;
 
@@ skipping 93 matching lines @@
   checkReturnInClass('B', 'returnInt8', typesTask.intType);
   checkReturnInClass('B', 'returnInt9', typesTask.intType);
 
   checkFactoryConstructor(String className, String factoryName) {
     var cls = findElement(compiler, className);
     var element = cls.localLookup(buildSourceString(factoryName));
     Expect.equals(new TypeMask.nonNullExact(cls.rawType),
                   typesInferrer.getReturnTypeOfElement(element));
   }
   checkFactoryConstructor('A', '');
+
+  checkReturn('testCascade1', typesTask.growableListType);
+  checkReturn('testCascade2', new TypeMask.nonNullExact(
+      typesTask.rawTypeOf(findElement(compiler, 'CascadeHelper'))));
 }