[clang] [C++20] [Modules] Support generating in-class defined function with try-catch body (PR #129212)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

> > Thanks, LGTM.
> > With just a little more effort you could add the EOF stuff in there too.
> 
> What do you mean by EOF stuff?

It seems you can deduplicate by moving this block into the scope guard:
```C++
      while (Tok.isNot(tok::eof))
        ConsumeAnyToken();
      if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
        ConsumeAnyToken();
```

https://github.com/llvm/llvm-project/pull/129212