[turbofan] Drop obsolete unused JSStrictNotEqual operator.

test/unittests/compiler/typer-unittest.cc

 // Copyright 2015 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 <functional>
 
 #include "src/codegen.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/operator-properties.h"
@@ skipping 338 matching lines @@
 }
 
 
 // For numbers there's no difference between strict and non-strict equality.
 TEST_F(TyperTest, TypeJSStrictEqual) {
   TestBinaryCompareOp(javascript_.StrictEqual(CompareOperationHint::kAny),
                       std::equal_to<double>());
 }
 
 
-TEST_F(TyperTest, TypeJSStrictNotEqual) {
-  TestBinaryCompareOp(javascript_.StrictNotEqual(CompareOperationHint::kAny),
-                      std::not_equal_to<double>());
-}
-
-
 //------------------------------------------------------------------------------
 // Monotonicity
 
 #define TEST_BINARY_MONOTONICITY(name)                                    \
   TEST_F(TyperTest, Monotonicity_##name) {                                \
     TestBinaryMonotonicity(javascript_.name(CompareOperationHint::kAny)); \
   }
 TEST_BINARY_MONOTONICITY(Equal)
 TEST_BINARY_MONOTONICITY(NotEqual)
 TEST_BINARY_MONOTONICITY(StrictEqual)
-TEST_BINARY_MONOTONICITY(StrictNotEqual)
 TEST_BINARY_MONOTONICITY(LessThan)
 TEST_BINARY_MONOTONICITY(GreaterThan)
 TEST_BINARY_MONOTONICITY(LessThanOrEqual)
 TEST_BINARY_MONOTONICITY(GreaterThanOrEqual)
 #undef TEST_BINARY_MONOTONICITY
 
 #define TEST_BINARY_MONOTONICITY(name)          \
   TEST_F(TyperTest, Monotonicity_##name) {      \
     TestBinaryMonotonicity(javascript_.name()); \
   }
@@ skipping 12 matching lines @@
 #define TEST_BINARY_MONOTONICITY(name)                                   \
   TEST_F(TyperTest, Monotonicity_##name) {                               \
     TestBinaryMonotonicity(javascript_.name(BinaryOperationHint::kAny)); \
   }
 TEST_BINARY_MONOTONICITY(Add)
 #undef TEST_BINARY_MONOTONICITY
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8