[turbofan] Properly implement %_ClassOf intrinsic.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 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.
 
 #include "src/compiler/js-generic-lowering.h"
 
 #include "src/ast/ast.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 125 matching lines @@
 
 void JSGenericLowering::LowerJSToBoolean(Node* node) {
   // The ToBoolean conversion doesn't need the current context.
   NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());
   Callable callable = CodeFactory::ToBoolean(isolate());
   node->AppendInput(zone(), graph()->start());
   ReplaceWithStubCall(node, callable, CallDescriptor::kNoAllocate,
                       Operator::kEliminatable);
 }
 
+void JSGenericLowering::LowerJSClassOf(Node* node) {
+  // The %_ClassOf intrinsic doesn't need the current context.
+  NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());
+  Callable callable = CodeFactory::ClassOf(isolate());
+  node->AppendInput(zone(), graph()->start());
+  ReplaceWithStubCall(node, callable, CallDescriptor::kNoAllocate,
+                      Operator::kEliminatable);
+}
+
 void JSGenericLowering::LowerJSTypeOf(Node* node) {
   // The typeof operator doesn't need the current context.
   NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());
   Callable callable = CodeFactory::Typeof(isolate());
   node->AppendInput(zone(), graph()->start());
   ReplaceWithStubCall(node, callable, CallDescriptor::kNoAllocate,
                       Operator::kEliminatable);
 }
 
 
@@ skipping 488 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8