dart2js cps: for(;;) is shorter than while(true)

pkg/compiler/lib/src/js_backend/codegen/codegen.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.
 
 library code_generator;
 
 import 'glue.dart';
 
 import '../../closure.dart' show
     ClosureClassElement;
@@ skipping 731 matching lines @@
       }
       js.Expression update = makeSequence(node.updates);
       loopNode = new js.For(init, condition, update, body);
     }
     accumulator.add(insertLabel(node.label, loopNode));
     visitStatement(node.next);
   }
 
   @override
   void visitWhileTrue(tree_ir.WhileTrue node) {
-    js.Expression condition = new js.LiteralBool(true);
     // A short break in the while will jump to the current fallthrough target.
     shortBreak.push(fallthrough.target);
     shortContinue.push(node);
     fallthrough.push(node);
     emitUnreachableAsReturn.add(true);
     js.Statement jsBody = buildBodyStatement(node.body);
     emitUnreachableAsReturn.removeLast();
     fallthrough.pop();
     shortContinue.pop();
     if (shortBreak.useCount > 0) {
       // Short breaks use the current fallthrough target.
       fallthrough.use();
     }
     shortBreak.pop();
-    accumulator.add(insertLabel(node.label, new js.While(condition, jsBody)));
+    accumulator.add(
+        insertLabel(node.label, new js.For(null, null, null, jsBody)));
   }
 
   bool isNull(tree_ir.Expression node) {
     return node is tree_ir.Constant && node.value.isNull;
   }
 
   @override
   void visitReturn(tree_ir.Return node) {
     if (isNull(node.value) && fallthrough.target == null) {
       // Do nothing. Implicitly return JS undefined by falling over the end.
@@ skipping 447 matching lines @@
   void registerDefaultParameterValues(ExecutableElement element) {
     if (element is! FunctionElement) return;
     FunctionElement function = element;
     if (function.isStatic) return; // Defaults are inlined at call sites.
     function.functionSignature.forEachOptionalParameter((param) {
       ConstantValue constant = glue.getDefaultParameterValue(param);
       registry.registerCompileTimeConstant(constant);
     });
   }
 }