[compiler] Introduce proper StrictNotEqualStub.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 3a61ef02d223770d8d7a40dbc6571e6d8d897e86..8be4618ff19a83b5072dd38828b9552140f8bcbd 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -102,6 +102,7 @@ namespace internal {
   /* TurboFanCodeStubs */                   \
   V(StringLength)                           \
   V(StrictEqual)                            \
+  V(StrictNotEqual)                         \
   V(ToBoolean)                              \
   /* IC Handler stubs */                    \
   V(ArrayBufferViewLoadField)               \
@@ -642,6 +643,16 @@ class StrictEqualStub final : public TurboFanCodeStub {
   DEFINE_CODE_STUB(StrictEqual, TurboFanCodeStub);
 };
 
+class StrictNotEqualStub final : public TurboFanCodeStub {
+ public:
+  explicit StrictNotEqualStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
+
+  void GenerateAssembly(compiler::CodeStubAssembler* assembler) const final;
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(Compare);
+  DEFINE_CODE_STUB(StrictNotEqual, TurboFanCodeStub);
+};
+
 class ToBooleanStub final : public TurboFanCodeStub {
  public:
   explicit ToBooleanStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}