Monday Patch Queue Review update (2022-06-06)

[Florian Weimer]

* Carlos O'Donell via Libc-alpha:

>  * Noah: Why can't we use #define to define rseq offset?
>   * Noah: Florian isn't here, and I was going to ask him the question.

This would make more of the thread descriptor/TCB layout part of the
ABI.  I guess we could do that for select ABIs if there is no concern
about future alignment requirements (e.g., if a future TCB requires 128
byte alignment, the rseq offset is a multiple of 32 from the TCB, but
not a multiple of 128, and a future rseq requires 64 byte alignment, we
would be in trouble).

Thanks,
Florian