[turbofan] Drop obsolete unused JSStrictNotEqual operator.

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 109 matching lines @@
 
 void JSGenericLowering::LowerJSStrictEqual(Node* node) {
   // The === operator doesn't need the current context.
   NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());
   Callable callable = CodeFactory::StrictEqual(isolate());
   node->RemoveInput(4);  // control
   ReplaceWithStubCall(node, callable, CallDescriptor::kNoFlags,
                       Operator::kEliminatable);
 }
 
-void JSGenericLowering::LowerJSStrictNotEqual(Node* node) {
-  // The !== operator doesn't need the current context.
-  NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());
-  Callable callable = CodeFactory::StrictNotEqual(isolate());
-  node->RemoveInput(4);  // control
-  ReplaceWithStubCall(node, callable, CallDescriptor::kNoFlags,
-                      Operator::kEliminatable);
-}
-
 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) {
@@ skipping 558 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8