Few tweaks to the generated code to avoid eg parenthesis.

lib/compiler/implementation/js/nodes.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.
 
 interface NodeVisitor<T> {
   T visitProgram(Program node);
 
   T visitBlock(Block node);
   T visitExpressionStatement(ExpressionStatement node);
   T visitEmptyStatement(EmptyStatement node);
@@ skipping 424 matching lines @@
 
   LiteralExpression(this.template) : inputs = const [];
   LiteralExpression.withData(this.template, this.inputs);
 
   accept(NodeVisitor visitor) => visitor.visitLiteralExpression(this);
 
   void visitChildren(NodeVisitor visitor) {
     for (Expression expr in inputs) expr.accept(visitor);
   }
 
-  int get precedenceLevel() => EXPRESSION;
+  // Code that uses JS must take care of operator precedences, and
+  // put parenthesis if needed.
+  int get precedenceLevel() => PRIMARY;
 }
 
 /**
  * [VariableDeclarationList] is a subclass of [Expression] to simplify the
  * AST.
  */
 class VariableDeclarationList extends Expression {
   final List<VariableInitialization> declarations;
 
   VariableDeclarationList(this.declarations);
@@ skipping 372 matching lines @@
   /** Contains the pattern and the flags.*/
   String pattern;
 
   RegExpLiteral(this.pattern);
 
   accept(NodeVisitor visitor) => visitor.visitRegExpLiteral(this);
   void visitChildren(NodeVisitor visitor) {}
 
   int get precedenceLevel() => PRIMARY;
 }