dart2dart: Logical operators and related rewrite rules in dart_tree.

sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart

Index: sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart b/sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart
index 6b4bc7a8f3ec5bf1267113f2b943f5bc05358be9..18f094da83938aa6209318e238df8320b28efbd7 100644
--- a/sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart
@@ -263,6 +263,16 @@ class ASTEmitter extends tree.Visitor<dynamic, Expression> {
         visitExpression(exp.elseExpression));
   }
 
+  Expression visitLogicalOperator(tree.LogicalOperator exp) {
+    return new BinaryOperator(visitExpression(exp.left),
+                              exp.operator,
+                              visitExpression(exp.right));
+  }
+
+  Expression visitNot(tree.Not exp) {
+    return new UnaryOperator('!', visitExpression(exp.operand));
+  }
+
   Expression visitVariable(tree.Variable exp) {
     return new Identifier(exp.name)
                ..element = exp.element;