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

pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
index 9ad19f0ca69c684832b87e506b750b77f62b5028..f4a26712472ae3c2705cbdeb887d45db32f7ca60 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
@@ -12,6 +12,7 @@ import '../dart2jslib.dart' as dart2js show invariant;
 import '../elements/elements.dart';
 import '../universe/universe.dart' show Selector, SelectorKind;
 import '../dart_types.dart' show DartType, GenericType;
+import 'package:compiler/src/js_backend/codegen/unsugar.dart';

[sigurdm, 2014/11/20 12:47:28]

Package import

 
 abstract class Node {
   static int hashCount = 0;
@@ -580,6 +581,8 @@ List<Reference<Primitive>> _referenceList(Iterable<Primitive> definitions) {
 }
 
 abstract class Visitor<T> {
+  const Visitor();
+
   T visit(Node node) => node.accept(this);
   // Abstract classes.
   T visitNode(Node node) => null;
@@ -618,11 +621,16 @@ abstract class Visitor<T> {
 
   // Conditions.
   T visitIsTrue(IsTrue node) => visitCondition(node);
+
+  // JavaScript specific nodes.
+  T visitBoolify(Boolify node) => visitIsTrue(node);
 }
 
 /// Recursively visits the entire CPS term, and calls abstract `process*`
 /// (i.e. `processLetPrim`) functions in pre-order.
 abstract class RecursiveVisitor extends Visitor {

[sigurdm, 2014/11/20 12:47:28]

Should implement

T visitBoolify(Boolify node) => processBoolify(node);

For consistency.

+  const RecursiveVisitor();
+
   // Ensures that RecursiveVisitor contains overrides for all relevant nodes.
   // As a rule of thumb, nodes with structure to traverse should be overridden
   // with the appropriate visits in this class (for example, visitLetCont),