dart2dart: Implementation of simple try/catch.

pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart

Index: pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
index 38d9c6f1935e0bc3d426467cc6bf827fbed7bb9c..e85182f2c1993e6d3126cf27e3f85f1cf4ba9f62 100644
--- a/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
+++ b/pkg/compiler/lib/src/tree_ir/tree_ir_tracer.dart
@@ -141,6 +141,11 @@ class BlockCollector extends StatementVisitor {
     ifTargets[node.next] = nextBlock;
   }
 
+  visitTryStatement(TryStatement node) {
+    // It's not obvious how we want to represent try statements here.

[karlklose, 2015/02/16 10:15:48]

Do you know what V8 or the SSA based backend do? Maybe we should just copy that.

+    // TODO(kmillikin).
+  }
+
   visitExpressionStatement(ExpressionStatement node) {
     _addStatement(node);
     visitStatement(node.next);
@@ -274,6 +279,11 @@ class TreeTracer extends TracerUtil with StatementVisitor, PassMixin {
     printStatement(null, "then $nextTarget" );
   }
 
+  visitTryStatement(TryStatement node) {
+    // It's not obvious how we want to represent try statements here.
+    // TODO(kmillikin).
+  }
+
   visitExpressionStatement(ExpressionStatement node) {
     printStatement(null, expr(node.expression));
   }