cps-ir: Implement boolean conversion in and use it to implement '&&', '||', and '?:'.

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 '../../tree_ir/tree_ir_nodes.dart' as tree_ir;
 import '../../js/js.dart' as js;
@@ skipping 61 matching lines @@
     }
 
     if (jsVariables.length > 0) {
       // Would be nice to avoid inserting at the beginning of list.
       accumulator.insert(0, new js.ExpressionStatement(
           new js.VariableDeclarationList(jsVariables)));
     }
     body = new js.Block(accumulator);
   }
 
+  js.Expression visit(tree_ir.Expression node) {
+    js.Expression result = node.accept(this);
+    if (result == null) {
+      glue.reportInternalError('$node did not produce code.');
+    }
+    return result;
+  }
+
   /// Generates a name for the given variable. First trying with the name of
   /// the [Variable.element] if it is non-null.
   String getVariableName(tree_ir.Variable variable) {
     // TODO(sigurdm): Handle case where the variable belongs to an enclosing
     // function.
     if (variable.host.element != currentFunction) giveup(variable);
 
     // Get the name if we already have one.
     String name = variableNames[variable];
     if (name != null) {
@@ skipping 29 matching lines @@
   }
 
   @override
   js.Expression visitConcatenateStrings(tree_ir.ConcatenateStrings node) {
     return giveup(node);
     // TODO: implement visitConcatenateStrings
   }
 
   @override
   js.Expression visitConditional(tree_ir.Conditional node) {
-    return giveup(node);
-    // TODO: implement visitConditional
+    return new js.Conditional(
+        visit(node.condition),
+        visit(node.thenExpression),
+        visit(node.elseExpression));
   }
 
   @override
   js.Expression visitConstant(tree_ir.Constant node) {
     ConstantValue constant = node.expression.value;
     registry.registerCompileTimeConstant(constant);
     return glue.constantReference(constant);
   }
 
   @override
@@ skipping 37 matching lines @@
   }
 
   @override
   js.Expression visitLiteralMap(tree_ir.LiteralMap node) {
     return giveup(node);
     // TODO: implement visitLiteralMap
   }
 
   @override
   js.Expression visitLogicalOperator(tree_ir.LogicalOperator node) {
-    return giveup(node);
-    // TODO: implement visitLogicalOperator
+    return new js.Binary(node.operator, visit(node.left), visit(node.right));
   }
 
   @override
   js.Expression visitNot(tree_ir.Not node) {
     return giveup(node);
     // TODO: implement visitNot
   }
 
   @override
   js.Expression visitReifyTypeVar(tree_ir.ReifyTypeVar node) {
@@ skipping 84 matching lines @@
   }
 
   @override
   void visitReturn(tree_ir.Return node) {
     accumulator.add(new js.Return(visitExpression(node.value)));
   }
 
   bool isNullLiteral(js.Expression exp) => exp is js.LiteralNull;
 
 }