atomic.S patch by mav

I am in for the assembler code patch. I will prepare an updated version.

I am definitely going to do that. But in the meantime we need a buildable stable/13 for i386. The solution I am proposing does (temporarily) place an additional file into cddl/lib/libspl what is outside of sys/contrib/openzfs.

I assume Brian just forgot to merge that commit or intentionally didn't merge that commit and did not inspect your commit for changes in that direction. The i386 build should be broken for Linux as well.

In D26311#676085, @avg wrote:

@mm , do you have amdgpio driver? Has it attached?

I get currently the following reply on stable/13 with an APU2 bios 4.13.0.4:
gpioleds0: <ACPI GPIO LEDs> on acpi0
gpioleds0: GPIO controller device \134_SB_.PCI0.GPIO is not attached
gpioleds0: GPIO controller device \134_SB_.PCI0.GPIO is not attached
gpioleds0: GPIO controller device \134_SB_.PCI0.GPIO is not attached
gpioleds0: detached

Thank you. We are testing Linux, FreeBSD, macOS (via GitHub Actions) and OmniOS (via Jenkins) on GitHub so that will tell how it behaves on other platforms.

If you don't know I am a core libarchive developer and release manager so getting the fix upstream is up to me.
I don't like modifying the framework this way, we should fix the individual test instead.