[clang] [clang] Update argument checking tablegen code to use a 'full' name (PR #99993)

[Mike Rice via cfe-commits]

mikerice1969 wrote:

> That code was added very recently by #94056 and seem to be specific to the `ptrauth_vtable_pointer` attribute. Perhaps we're lacking test coverage if nothing breaks without that code?

@AaronBallman The code is logically useless so there's no way to add tests that make it useful.

```
do {
  if (Tok.is(tok::identifier) && attributeHasStrictIdentifierArgAtIndex()) {
    ArgExprs.push_back(ParseIdentifierLoc());   
    continue;
  }
  if (Tok.is(tok::identifier)) {             
    ArgExprs.push_back(ParseIdentifierLoc());
  } else {
    // Do something if not an identifier
  }
} while (TryConsumeToken(tok::comma);
```
It doesn't matter what attributeHasStrictIdentifierArgAtIndex returns we will always just add identifiers to ArgExprs.
The only question is what was intended in the code.

Unless @ojhunt and/or @ahmedbougacha can clarify I think we should just remove it.


https://github.com/llvm/llvm-project/pull/99993