[stubs] Introduce AddStub and SubtractStub.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 5bf8c3e8b7e93062fb8ecadb520bf4381f4fed63..66d409abbf006e560ee38a114decb1fa62e0e0ce 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -111,6 +111,8 @@ namespace internal {
   V(AllocateUint8x16)                       \
   V(AllocateBool8x16)                       \
   V(StringLength)                           \
+  V(Add)                                    \
+  V(Subtract)                               \
   V(LessThan)                               \
   V(LessThanOrEqual)                        \
   V(GreaterThan)                            \
@@ -667,6 +669,22 @@ class StringLengthStub : public TurboFanCodeStub {
   DEFINE_TURBOFAN_CODE_STUB(StringLength, TurboFanCodeStub);
 };
 
+class AddStub final : public TurboFanCodeStub {
+ public:
+  explicit AddStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(BinaryOp);
+  DEFINE_TURBOFAN_CODE_STUB(Add, TurboFanCodeStub);
+};
+
+class SubtractStub final : public TurboFanCodeStub {
+ public:
+  explicit SubtractStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(BinaryOp);
+  DEFINE_TURBOFAN_CODE_STUB(Subtract, TurboFanCodeStub);
+};
+
 class LessThanStub final : public TurboFanCodeStub {
  public:
   explicit LessThanStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}