Infer SendSet node correctly.

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 'compiler_helper.dart';
+import 'parser_helper.dart';
 
 const String TEST = """
 returnNum1(a) {
   if (a) return 1;
   else return 2.0;
 }
 
 returnNum2(a) {
   if (a) return 1.0;
   else return 2;
 }
 
-returnInt(a) {
+returnInt1(a) {
   if (a) return 1;
   else return 2;
 }
 
 returnDouble(a) {
   if (a) return 1.0;
   else return 2.0;
 }
 
 returnGiveUp(a) {
   if (a) return 1;
   else return 'foo';
 }
 
+returnInt2() {
+  var a = 42;
+  return a++;
+}
+
+returnNum3() {
+  var a = 42;
+  return ++a;
+}
+
+returnNum4() {
+  var a = 42;
+  a++;
+  return a;
+}
+
+class A {
+  get myField => 42;
+  set myField(a) {}
+  returnNum1() => ++myField;
+  returnNum2() => ++this.myField;
+  returnNum3() => this.myField += 42;
+  returnNum4() => myField += 42;
+  operator[](index) => 42;
+  operator[]= (index, value) {}
+  returnNum5() => ++this[0];
+  returnNum6() => this[0] += 1;
+}
+
+class B extends A {
+  returnNum1() => ++new A().myField;
+  returnNum2() => new A().myField += 4;
+  returnNum3() => ++new A()[0];
+  returnNum4() => new A()[0] += 42;
+  returnNum5() => ++super.myField;
+  returnNum6() => super.myField += 4;
+  returnNum7() => ++super[0];
+  returnNum8() => super[0] += 54;
+}
+
 main() {
   returnNum1(true);
   returnNum2(true);
-  returnInt(true);
+  returnInt1(true);
+  returnInt2(true);
   returnDouble(true);
   returnGiveUp(true);
+  returnNum3();
+  returnNum4();
+  new A()..returnNum1()
+         ..returnNum2()
+         ..returnNum3()
+         ..returnNum4()
+         ..returnNum5()
+         ..returnNum6();
+
+  new B()..returnNum1()
+         ..returnNum2()
+         ..returnNum3()
+         ..returnNum4()
+         ..returnNum5()
+         ..returnNum6()
+         ..returnNum7()
+         ..returnNum8();
 }
 """;
 
 void main() {
   Uri uri = new Uri.fromComponents(scheme: 'source');
   var compiler = compilerFor(TEST, uri);
   compiler.runCompiler(uri);
   var typesInferrer = compiler.typesTask.typesInferrer;
 
-  var element = findElement(compiler, 'returnNum1');
-  Expect.equals(compiler.numClass, typesInferrer.returnTypeOf[element]);
+  checkReturn(String name, type) {
+    var element = findElement(compiler, name);
+    Expect.equals(type, typesInferrer.returnTypeOf[element]);
+  }
+  checkReturn('returnNum1', compiler.numClass);
+  checkReturn('returnNum2', compiler.numClass);
+  checkReturn('returnInt1', compiler.intClass);
+  checkReturn('returnInt2', compiler.intClass);
+  checkReturn('returnDouble', compiler.doubleClass);
+  checkReturn('returnGiveUp', typesInferrer.giveUpType);
+  checkReturn('returnNum3', compiler.numClass);
+  checkReturn('returnNum4', compiler.numClass);
 
-  element = findElement(compiler, 'returnNum2');
-  Expect.equals(compiler.numClass, typesInferrer.returnTypeOf[element]);
+  checkReturnInClass(String className, String methodName, type) {
+    var cls = findElement(compiler, className);
+    var element = cls.lookupLocalMember(buildSourceString(methodName));
+    Expect.equals(type, typesInferrer.returnTypeOf[element]);
+  }
 
-  element = findElement(compiler, 'returnInt');
-  Expect.equals(compiler.intClass, typesInferrer.returnTypeOf[element]);
+  checkReturnInClass('A', 'returnNum1', compiler.numClass);
+  checkReturnInClass('A', 'returnNum2', compiler.numClass);
+  checkReturnInClass('A', 'returnNum3', compiler.numClass);
+  checkReturnInClass('A', 'returnNum4', compiler.numClass);
+  checkReturnInClass('A', 'returnNum5', compiler.numClass);
+  checkReturnInClass('A', 'returnNum6', compiler.numClass);
 
-  element = findElement(compiler, 'returnDouble');
-  Expect.equals(compiler.doubleClass, typesInferrer.returnTypeOf[element]);
-
-  element = findElement(compiler, 'returnGiveUp');
-  Expect.equals(typesInferrer.giveUpType, typesInferrer.returnTypeOf[element]);
+  checkReturnInClass('B', 'returnNum1', compiler.numClass);
+  checkReturnInClass('B', 'returnNum2', compiler.numClass);
+  checkReturnInClass('B', 'returnNum3', compiler.numClass);
+  checkReturnInClass('B', 'returnNum4', compiler.numClass);
+  checkReturnInClass('B', 'returnNum5', compiler.numClass);
+  checkReturnInClass('B', 'returnNum6', compiler.numClass);
+  checkReturnInClass('B', 'returnNum7', compiler.numClass);
+  checkReturnInClass('B', 'returnNum8', compiler.numClass);
 }