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

pkg/compiler/lib/src/js_backend/codegen/task.dart

Index: pkg/compiler/lib/src/js_backend/codegen/task.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/task.dart b/pkg/compiler/lib/src/js_backend/codegen/task.dart
index 5b6e303edb87f7d3457e3484267b304a40abc370..6a61a001ad99e63d29d798acf4f95a3a9fe8d2dc 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/task.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/task.dart
@@ -7,6 +7,7 @@ library code_generator_task;
 
 import 'glue.dart';
 import 'codegen.dart';
+import 'unsugar.dart';
 
 import '../js_backend.dart';
 import '../../dart2jslib.dart';
@@ -99,6 +100,7 @@ class CspFunctionCompiler implements FunctionCompiler {
     if (cpsNode == null) {
       giveUp('unable to build cps definition of $element');
     }
+    const UnsugarVisitor().rewrite(cpsNode);
     return cpsNode;
   }