[crankshaft] Fix IsClassOfTest helper method

src/ast/ast.cc

Index: src/ast/ast.cc
diff --git a/src/ast/ast.cc b/src/ast/ast.cc
index 4ec0a9f8f95e344f595b3e02aa7e1fbd20546006..75a911ea54ec3703bb4941532945f8169f7ddf92 100644
--- a/src/ast/ast.cc
+++ b/src/ast/ast.cc
@@ -28,6 +28,8 @@ namespace internal {
 
 #ifdef DEBUG
 
+void AstNode::Print() { Print(Isolate::Current()); }
+
 void AstNode::Print(Isolate* isolate) {
   AstPrinter::PrintOut(isolate, this);
 }