dart2js cps: Generate increment and compound operators.

tests/compiler/dart2js/js_backend_cps_ir_closures_test.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.
 
 // Tests of closures.
 
 library closures_test;
 
 import 'js_backend_cps_ir.dart';
 
@@ skipping 88 matching lines @@
   var a = () => x;
   x = x + 1;
   print(a());
   return a;
 }
 """,
 r"""
 function() {
   var _box_0 = {}, a = new V.main_closure(_box_0), v0;
   _box_0.x = 122;
-  _box_0.x = _box_0.x + 1;
+  ++_box_0.x;
   v0 = H.S(a.call$0());
   if (typeof dartPrint == "function")
     dartPrint(v0);
   else if (typeof console == "object" && typeof console.log != "undefined")
     console.log(v0);
   else if (!(typeof window == "object")) {
     if (!(typeof print == "function"))
       throw "Unable to print message: " + String(v0);
     print(v0);
   }
@@ skipping 34 matching lines @@
   };
   x = x + 1;
   print(a()());
   return a;
 }
 """,
 r"""
 function() {
   var _box_0 = {}, a = new V.main_closure(_box_0), v0;
   _box_0.x = 122;
-  _box_0.x = _box_0.x + 1;
+  ++_box_0.x;
   v0 = H.S(a.call$0().call$0());
   if (typeof dartPrint == "function")
     dartPrint(v0);
   else if (typeof console == "object" && typeof console.log != "undefined")
     console.log(v0);
   else if (!(typeof window == "object")) {
     if (!(typeof print == "function"))
       throw "Unable to print message: " + String(v0);
     print(v0);
   }
   return a;
 }"""),
 
   const TestEntry("""
 main() {
   var a;
   for (var i=0; i<10; i++) {
     a = () => i;
   }
   print(a());
 }
 """,
 r"""
 function() {
   var a = null, i = 0, v0;
-  for (; i < 10; a = new V.main_closure(i), i = i + 1)
+  for (; i < 10; a = new V.main_closure(i), ++i)
     ;
   v0 = H.S(a.call$0());
   if (typeof dartPrint == "function")
     dartPrint(v0);
   else if (typeof console == "object" && typeof console.log != "undefined")
     console.log(v0);
   else if (!(typeof window == "object")) {
     if (!(typeof print == "function"))
       throw "Unable to print message: " + String(v0);
     print(v0);
@@ skipping 106 matching lines @@
 function(x) {
   V.Foo$();
   P.print("getter");
   P.print(new V.Foo_getter_closure().call$1(123));
 }"""),
 ];
 
 void main() {
   runTests(tests);
 }