[PATCH 00/12] address most remaining Misra rule 2.1 violations

Let's try to get the unreachable code rule almost clean: With this series
in place, as per [1] x86_64-allcode has one violation left, x86_64-amd has
two; ARM64-* are clean. But see also "gnttab: unreachable code when
GNTTAB_MAX_VERSION < 2" [2].

The first two thirds of this series are hopefully largely uncontroversial,
whereas the last third may be.

01: x86/IO-APIC: address Misra 2.1 rule violations
02: x86/mm: pagetable_dying() is HVM+SHADOW_PAGING only
03: x86/shadow: eliminate unused forms of sh_map_and_validate_gl<N>e()
04: x86: add noreturn in a few more places
05: x86/crash: address Misra 2.1 rule violation
06: kexec: machine_reboot_kexec() doesn't return
07: altp2m: address Misra 2.1 rule violation
08: Arm/GIC: add noreturn in a few more places
09: Eclair: deviate BUILD_ERROR() wrt rule 2.1 and introduce variants
10: PCI/physdev: address Misra 2.1 rule violation
11: x86/HVM: address Misra 2.1 rule violations
12: x86/nSVM: address Misra 2.1 rule violation

Jan

[1] https://gitlab.com/xen-project/hardware/xen-staging/-/pipelines/2796557177
[2] https://lists.xen.org/archives/html/xen-devel/2026-07/msg01293.html