rpm: build and package debug hypervisor

[marmarek]

Ease debugging by building a separate subpackage with debug hypervisor.
It's installed as xen-debug-(version).

QubesOS/qubes-issues#5989

[marmarek]

The way currently grub.cfg is generated puts the debug version as the default one (xen-debug-4.17.2.gz sorts as newer than xen-4.17.2.gz). I don't like it. The question is what would be a better approach. Some options:

• name it xen-0-debug-4.17.2.gz - it will make it non-default without changing grub config generator
• adjust grub to sort debug one specifically at the end
• adjust grub to put debug into separate section (might be an overkill, given rare need for this package)
• something else?

Any opinions @HW42 @DemiMarie ?

[HW42]

I think the options to adjust grub are the cleanest. Menu indeed likely overkill. xen-0-debug-... is ugly, but acceptable.

[DemiMarie]

I would prefer for debugging to be a separate section. I agree that even if the debug hypervisor is installed, it should not be booted by default.