Few tweaks to the generated code to avoid eg parenthesis.

lib/compiler/implementation/ssa/codegen.dart

 // Copyright (c) 2012, 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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   final JavaScriptBackend backend;
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
         super(backend.compiler);
   String get name() => 'SSA code generator';
@@ skipping 71 matching lines @@
       Map<Element, String> parameterNames = getParameterNames(work);
       List<js.Parameter> parameters = <js.Parameter>[];
       parameterNames.forEach((element, name) {
         parameters.add(new js.Parameter(name));
       });
       SsaUnoptimizedCodeGenerator codegen = new SsaUnoptimizedCodeGenerator(
           backend, work, parameters, parameterNames);
       codegen.visitGraph(graph);
 
       js.Block body = new js.Block(<js.Statement>[]);
-      body.statements.add(codegen.setup);
+      if (codegen.setup != null) body.statements.add(codegen.setup);
       body.statements.add(codegen.body);
       js.Fun fun =
           buildJavaScriptFunction(work.element, codegen.newParameters, body);
       return prettyPrint(fun, work.element);
     });
   }
 
   Map<Element, String> getParameterNames(WorkItem work) {
     Map<Element, String> parameterNames = new LinkedHashMap<Element, String>();
     FunctionElement function = work.element;
@@ skipping 2492 matching lines @@
    * bailout-switches just push [:false:] on the stack and replace it when
    * they used the [:default::] clause.
    */
   final List<bool> defaultClauseUsedInBailoutStack;
 
   SsaBailoutPropagator propagator;
   HInstruction savedFirstInstruction;
 
   SsaUnoptimizedCodeGenerator(backend, work, parameters, parameterNames)
     : super(backend, work, parameterNames),
-      setup = new js.EmptyStatement(),
       oldBailoutSwitches = <js.Switch>[],
       newParameters = <js.Parameter>[],
       labels = <String>[],
       defaultClauseUsedInBailoutStack = <bool>[];
 
   String pushLabel() {
     String label = 'L${labelId++}';
     labels.addLast(label);
     return label;
   }
@@ skipping 294 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }