[stubs] Introduce ToIntegerStub and unify the handling of %_ToInteger.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 14133b39b0d3df321b6b9939d1af96fd2fd0341d..ace4aae6142341012de8eb887ae2c3b1afc8b26c 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -130,6 +130,7 @@ namespace internal {
   V(StringGreaterThan)                      \
   V(StringGreaterThanOrEqual)               \
   V(ToBoolean)                              \
+  V(ToInteger)                              \
   V(ToLength)                               \
   /* IC Handler stubs */                    \
   V(ArrayBufferViewLoadField)               \
@@ -836,6 +837,14 @@ class ToBooleanStub final : public TurboFanCodeStub {
   DEFINE_TURBOFAN_CODE_STUB(ToBoolean, TurboFanCodeStub);
 };
 
+class ToIntegerStub final : public TurboFanCodeStub {
+ public:
+  explicit ToIntegerStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(TypeConversion);
+  DEFINE_TURBOFAN_CODE_STUB(ToInteger, TurboFanCodeStub);
+};
+
 class ToLengthStub final : public TurboFanCodeStub {
  public:
   explicit ToLengthStub(Isolate* isolate) : TurboFanCodeStub(isolate) {}