[clang] [Clang] [Sema] Handle `this` in `__restrict`-qualified member functions properly (PR #83187)

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Sirraide wrote:

> > however, GCC accepts this; should we do so as well?
> 
> If so, should that be a separate pr, perhaps?

@AaronBallman If you think it’s related enough I can look into this as well for this pr; otherwise, I’m gonna go ahead and merge this one and then probably look into that next because it would make sense to support that imo if it’s not too complicated to implement.

https://github.com/llvm/llvm-project/pull/83187