Restart AST node numbering when we enter a function.

src/prettyprinter.cc

Index: src/prettyprinter.cc
diff --git a/src/prettyprinter.cc b/src/prettyprinter.cc
index 043ad1ca48ab86b6be30939ca213e1fae9980a36..3be571f348235d6cf97dc282edbd199af2501a7e 100644
--- a/src/prettyprinter.cc
+++ b/src/prettyprinter.cc
@@ -1,4 +1,4 @@
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -1008,6 +1008,7 @@ void AstPrinter::VisitVariableProxy(VariableProxy* node) {
 
 void AstPrinter::VisitAssignment(Assignment* node) {
   IndentedScope indent(this, Token::Name(node->op()), node);
+  Print("%d ", node->id());
   Visit(node->target());
   Visit(node->value());
 }