dart2dart: Implementation of simple try/catch.

pkg/compiler/lib/src/use_unused_api.dart

Index: pkg/compiler/lib/src/use_unused_api.dart
diff --git a/pkg/compiler/lib/src/use_unused_api.dart b/pkg/compiler/lib/src/use_unused_api.dart
index 0ba3b3d6a37b416e9cb01aca8e8bedd35462854e..bf443220f47aab2c0d28c207f80faad4b3b5cc49 100644
--- a/pkg/compiler/lib/src/use_unused_api.dart
+++ b/pkg/compiler/lib/src/use_unused_api.dart
@@ -63,7 +63,7 @@ void main(List<String> arguments) {
   useCodeBuffer(null);
   usedByTests();
   useElements(null, null, null, null, null);
-  useIr(null, null, null);
+  useIr(null, null);
   useCompiler(null);
   useTypes();
   useCodeEmitterTask(null);
@@ -238,23 +238,8 @@ useElements(
   pfe.copyWithEnclosing(null);
 }
 
-useIr(cps_ir_nodes_sexpr.SExpressionStringifier stringifier,
-      ir_builder.IrBuilderTask task,
+useIr(ir_builder.IrBuilderTask task,
       ir_builder.IrBuilder builder) {
-  new cps_ir_nodes_sexpr.SExpressionStringifier();
-  stringifier
-    ..newContinuationName(null)
-    ..newValueName(null)
-    ..visitConstant(null)
-    ..visitContinuation(null)
-    ..visitDefinition(null)
-    ..visitExpression(null)
-    ..visitFunctionDefinition(null)
-    ..visitFieldDefinition(null)
-    ..visitInvokeStatic(null)
-    ..visitLetCont(null)
-    ..visitNode(null)
-    ..visitParameter(null);
   task
     ..hasIr(null)
     ..getIr(null);