Backporting minor fix to older gdb releases

[Luis Machado]

Hi,

I have a small issue (fixed in gdb 13 via commit 1ba3a3222039eb2576d29c9fd3af444f59fa51d2) that I'd like to backport
a fix to at least gdb 12 and gdb 11.

I did, however, notice that it is easily backportable to gdb 10 and gdb 9, versions also affected by the same bug.

Given the backport is small and helps prevent crashes when connecting to a QEMU that supports pointer authentication,
I'm wondering what global maintainers think about it.

If distros want to pick up the fix, they can do so without having to worry about conflicts.

What do you think?

Thanks,
Luis