dart2dart: Implementation of simple try/catch.

pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart

Index: pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
diff --git a/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart b/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
index abf3627ff4852396e2821659d0883a29bf8a5de8..2a9ee3eb74a6fe9451c0e36f253220c8fd1ecd5b 100644
--- a/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
+++ b/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
@@ -171,6 +171,12 @@ class LogicalRewriter extends Visitor<Statement, Expression> with PassMixin {
     return node;
   }
 
+  Statement visitTryStatement(TryStatement node) {
+    node.tryBody = visitStatement(node.tryBody);
+    node.catchBody = visitStatement(node.catchBody);
+    return node;
+  }
+
   Statement visitExpressionStatement(ExpressionStatement node) {
     node.expression = visitExpression(node.expression);
     node.next = visitStatement(node.next);