Implement visitCascade/visitCascadeReceiver in inferrer_visitor.dart

tests/compiler/dart2js/simple_inferrer_test.dart

Index: tests/compiler/dart2js/simple_inferrer_test.dart
diff --git a/tests/compiler/dart2js/simple_inferrer_test.dart b/tests/compiler/dart2js/simple_inferrer_test.dart
index 14ef813474694ef6c7ef24ff0fbea42073270923..eabe4c3a8840ab8b8d516c70142b9efcd432c34c 100644
--- a/tests/compiler/dart2js/simple_inferrer_test.dart
+++ b/tests/compiler/dart2js/simple_inferrer_test.dart
@@ -404,6 +404,22 @@ class B extends A {
   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;
@@ -478,6 +494,8 @@ main() {
   testReturnElementOfConstList2();
   testReturnItselfOrInt(topLevelGetter());
   testReturnInvokeDynamicGetter();
+  testCascade1();
+  testCascade2();
 }
 """;
 
@@ -591,4 +609,8 @@ void main() {
                   typesInferrer.getReturnTypeOfElement(element));
   }
   checkFactoryConstructor('A', '');
+
+  checkReturn('testCascade1', typesTask.growableListType);
+  checkReturn('testCascade2', new TypeMask.nonNullExact(
+      typesTask.rawTypeOf(findElement(compiler, 'CascadeHelper'))));
 }