[regexp] Remove remainder of native RegExpExecStub

src/code-factory.h

Index: src/code-factory.h
diff --git a/src/code-factory.h b/src/code-factory.h
index 669f3798aaed0849b81cd3140ecc949d8bd5899a..e5653b823d513368a8b7d806db1d178f98d5c552 100644
--- a/src/code-factory.h
+++ b/src/code-factory.h
@@ -91,8 +91,6 @@ class V8_EXPORT_PRIVATE CodeFactory final {
                                       OrdinaryToPrimitiveHint hint);
   static Callable NumberToString(Isolate* isolate);
 
-  static Callable RegExpExec(Isolate* isolate);
-
   static Callable Add(Isolate* isolate);
   static Callable Subtract(Isolate* isolate);
   static Callable Multiply(Isolate* isolate);