[crankshaft] Fix IsClassOfTest helper method

Drive-by-fix: Add AstNode::Print() and improve printing of CallRuntime
              Expression.

BUG=v8:5749

Review-Url: https://codereview.chromium.org/2586933002
Cr-Commit-Position: refs/heads/master@{#41792}

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);
 }

src/ast/ast.h

@@ -191,6 +191,7 @@ class AstNode: public ZoneObject {
   int position() const { return position_; }
 
 #ifdef DEBUG
+  void Print();
   void Print(Isolate* isolate);
 #endif  // DEBUG
 

src/ast/prettyprinter.cc

@@ -1142,7 +1142,13 @@ void AstPrinter::VisitCallNew(CallNew* node) {
 
 void AstPrinter::VisitCallRuntime(CallRuntime* node) {
   EmbeddedVector<char, 128> buf;
-  SNPrintF(buf, "CALL RUNTIME %s", node->debug_name());
+  if (node->is_jsruntime()) {
+    SNPrintF(buf, "CALL RUNTIME %s code = %p", node->debug_name(),
+             isolate_->context()->get(node->context_index()));
+  } else {
+    SNPrintF(buf, "CALL RUNTIME %s", node->debug_name());
+  }
+
   IndentedScope indent(this, buf.start(), node->position());
   PrintArguments(node->arguments());
 }

src/crankshaft/hydrogen.cc

@@ -10924,15 +10924,12 @@ static bool IsClassOfTest(CompareOperation* expr) {
   Literal* literal = expr->right()->AsLiteral();
   if (literal == NULL) return false;
   if (!literal->value()->IsString()) return false;
-  if (!call->is_jsruntime() &&
-      call->function()->function_id != Runtime::kInlineClassOf) {
-    return false;
-  }
-  DCHECK(call->arguments()->length() == 1);
+  if (call->is_jsruntime()) return false;
+  if (call->function()->function_id != Runtime::kInlineClassOf) return false;
+  DCHECK_EQ(call->arguments()->length(), 1);
   return true;
 }
 
-
 void HOptimizedGraphBuilder::VisitBinaryOperation(BinaryOperation* expr) {
   DCHECK(!HasStackOverflow());
   DCHECK(current_block() != NULL);

test/mjsunit/regress/regress-5749.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+function f(x) {
+    (x ** 1) === '';
+}
+f();
+f();
+f();
+%OptimizeFunctionOnNextCall(f);
+f();
+
+function g(x) {
+    '' === (x ** 1);
+}
+g();
+g();
+g();
+%OptimizeFunctionOnNextCall(g);
+g();