[llvm] [TableGen][NFC] Add record kind to `Record` class (PR #69919)

[Francesco Petrogalli via llvm-commits]

================
@@ -1650,6 +1650,8 @@ class Record {
     DumpInfo(SMLoc Loc, Init *Message) : Loc(Loc), Message(Message) {}
   };
 
+  enum RecordKind { RK_Normal, RK_Anonymous, RK_Class, RK_MultiClass };
----------------
fpetrogalli wrote:

May I suggest the following rename? Seems to be more straightforward...
```suggestion
  enum RecordKind { RK_Def, RK_AnonymousDef, RK_Class, RK_MultiClass };
```




https://github.com/llvm/llvm-project/pull/69919