dart2dart: Implementation of simple try/catch.

pkg/compiler/lib/src/cps_ir/cps_ir_tracer.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 dart2js.ir_tracer;
 
 import 'dart:async' show EventSink;
 
 import 'cps_ir_nodes.dart' as cps_ir hide Function;
 import '../tracer.dart';
@@ skipping 102 matching lines @@
     if (IR_TRACE_LET_CONT) {
       String dummy = names.name(node);
       for (cps_ir.Continuation continuation in node.continuations) {
         String id = names.name(continuation);
         printStmt(dummy, "LetCont $id = <$id>");
       }
     }
     visit(node.body);
   }
 
+  visitLetHandler(cps_ir.LetHandler node) {
+    if (IR_TRACE_LET_CONT) {
+      String dummy = names.name(node);
+      String id = names.name(node.handler);
+      printStmt(dummy, "LetHandler $id = <$id>");
+    }
+    visit(node.body);
+  }
+
   visitLetMutable(cps_ir.LetMutable node) {
     String id = names.name(node.variable);
     printStmt(id, "${node.runtimeType} $id = ${formatReference(node.value)}");
     visit(node.body);
   }
 
   visitInvokeStatic(cps_ir.InvokeStatic node) {
     String dummy = names.name(node);
     String callName = node.selector.name;
     String args = node.arguments.map(formatReference).join(', ');
@@ skipping 295 matching lines @@
 
   visitLetPrim(cps_ir.LetPrim exp) {
     visit(exp.body);
   }
 
   visitLetCont(cps_ir.LetCont exp) {
     exp.continuations.forEach(visit);
     visit(exp.body);
   }
 
+  visitLetHandler(cps_ir.LetHandler exp) {
+    visit(exp.handler);
+    visit(exp.body);
+  }
+
+  visitLetMutable(cps_ir.LetMutable exp) {
+    visit(exp.body);
+  }
+
   void addEdgeToContinuation(cps_ir.Reference continuation) {
     cps_ir.Definition target = continuation.definition;
     if (target is cps_ir.Continuation && !target.isReturnContinuation) {
       current_block.addEdgeTo(getBlock(target));
     }
   }
 
   visitInvokeStatic(cps_ir.InvokeStatic exp) {
     addEdgeToContinuation(exp.continuation);
   }
@@ skipping 37 matching lines @@
     }
   }
 
   visitContinuation(cps_ir.Continuation c) {
     var old_node = current_block;
     current_block = getBlock(c);
     visit(c.body);
     current_block = old_node;
   }
 }