Adding AstNode::PrettyPrint and AstNode::PrintAst

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index 7f00955a644fcaeeeca1be192c67a5afa7ec0b70..a81f16742481332d61bac3e42b6fd67577977cdf 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -196,6 +196,13 @@ class AstNode: public ZoneObject {
   virtual NodeType node_type() const = 0;
   int position() const { return position_; }
 
+#ifdef DEBUG
+  void PrettyPrint(Isolate* isolate);
+  void PrettyPrint();
+  void PrintAst(Isolate* isolate);
+  void PrintAst();
+#endif  // DEBUG
+
   // Type testing & conversion functions overridden by concrete subclasses.
 #define DECLARE_NODE_FUNCTIONS(type) \
   bool Is##type() const { return node_type() == AstNode::k##type; } \