Fix ppc64le and s390x builds if possible

[jmontleon]

Builds are failing on ppc64le and s390x.

I see a number of fixes going into the pytorch repo to address build issues on these architectures, but I am uncertain if we should expect successful builds at this time. I wanted to build with main today to see if there has been any improvement since 2.0.1, but there is an issue confirmed on status.fedoraproject.org with Copr so I'll have to wait to see.

[jmontleon]

At least part seems to be the change in clang 16 wrt to Wimplicit-function-declaration
https://www.redhat.com/en/blog/new-warnings-and-errors-clang-16

Though that doesn't explain the clang 15 build errors on rhel 9/epel.

[jmontleon]

I filed an issue against cpuinfo pytorch/cpuinfo#171 to see if we can get a hand with a proper fix for this.

The clang 15 s390x build looks like it might finish successfully, so if we can get past this maybe the others will work as well.

[jmontleon]

I believe there is a small fix required to cpuinfo. I've update the issue on the git repo. This fixes s390x builds and partially fixes ppc64le builds. I'll submit a PR with the patch here shortly, once I've confirmed it's not unexpectedly breaking any other targets.

[jmontleon]

I believe this fixes another ppc64le issue. The build is progressing further; will need to see if it actually finishes.
pytorch/pytorch#98511

I've also been making most my attempts on main, so I need to determine whether there's anything else between 2.0.1 and main needed for builds to work.

[jmontleon]

We're also seeing this failure, for which it doesn't look like there is a solution yet.
pytorch/pytorch#91936

[jmontleon]

@trixirt I saw you have cpuinfo built in rawhide over at https://src.fedoraproject.org/rpms/cpuinfo

Frustratingly, even though cpuinfo doesn't work on s390x and ppc64le, as far as I can tell it compiles fine and remains a dependency of pytorch. Would you be OK with a PR against the repo to enable and fix the builds for other archs?