Backporting minor fix to older gdb releases

[Luis Machado]

On 3/15/23 13:11, Joel Brobecker via Gdb wrote:
> FWIW, there is no real policy that I know of.
> 
> We have been known to accept patches on release branches past the .2
> release. It's been very rare, though. In all cases, the push was done
> with the understanding that there would likely not be another official
> release off that branch, so that was purely for the benefit of people
> who wanted to build from the HEAD of a release branch rather than from
> an official release.
> 
> Whether we should be doing it in this case, I don't have a strong
> opinion. I think Andrew is making good points, and I'm wondering
> whether it will actually serve anyone if we backport the patches.
> On the other hand, are the patches extra safe? If they are, perhaps
> in the spirit of not standing in the way of someone willing to make
> it better for others...
> 

All reasonable points, I agree.

The patch (a single one) is mostly trivial reordering of code to fix a pseudo-register
number that we get wrong for the pauth feature. It helps in that it allows people to use
gdb 9/10/11/12 with a new qemu. Otherwise those gdb's will just crash on connection, with no
way around it.