Enable clone3() syscall on SPARC which was added in Linux v7.0

[glaubitz]

clone3() has been added for SPARC in Linux v7.0, thus enable it.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[tgross35]

Deleting the comments in src/ is fine, but we of course can't unskip the tests until things pass. Could you just update that comment to mention the kernel version?

Also, do you have a link to the relevant source?

[glaubitz]

Deleting the comments in src/ is fine, but we of course can't unskip the tests until things pass. Could you just update that comment to mention the kernel version?

Ah, I wasn't aware that the tests are run against the kernel headers.

So, I guess I will wait with the PR until the build environment for the CI is recent enough. I don't think it makes much sense to just remove the comments for now.

Also, do you have a link to the relevant source?

The commit to add clone3() for SPARC is this one: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/sparc?id=2153b2e8917b73e9e7fae8963f03b8e60bd8f5ff

It requires an additional fix to land first: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/sparc?id=e38eba3b77878ada327a572a41596a3b0b44e522

[tgross35]

In that case,

@rustbot blocked

Should be able to update once https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md bumps the kernel version, or probably once the 26.04 images are out.