Add testing on powerpc to the github CI

[powerboat9]

This should help solve #2184

[powerboat9]

A file last modified before I was born is failing to compile because it intentionally uses implicit function declarations

[dkm]

erm, darwin ppc (original report) is a native target without rustc support, and you're adding a cross target, still without rustc support, but it's even worse as we don't support cross compilation yet.

Do we really want to add this?

[thesamesam]

My own take (as someone who cares very much about GCC and Rust portability in the long-term) is that it's not worth spending time on this yet.

[philberty]

This is fantastic the only change i would make is i think it shouldnt be part of ccpp.yml workflow on pull requests but make it its own workflow like the bootstrap one where it runs on a cron and we add the build-badge to the readme

[powerboat9]

erm, darwin ppc (original report) is a native target without rustc support, and you're adding a cross target, still without rustc support, but it's even worse as we don't support cross compilation yet.

Do we really want to add this?

I was thinking this would be good for making sure we don't break big endian back ends, but if rustc doesn't support it, it would be impossible at this point to compile the rust libraries we use. Would probably be good to leave this unmerged for now, although the CI logs on this PR might help us troubleshoot anyways.

[dkm]

erm, darwin ppc (original report) is a native target without rustc support, and you're adding a cross target, still without rustc support, but it's even worse as we don't support cross compilation yet.
Do we really want to add this?

I was thinking this would be good for making sure we don't break big endian back ends, but if rustc doesn't support it, it would be impossible at this point to compile the rust libraries we use. Would probably be good to leave this unmerged for now, although the CI logs on this PR might help us troubleshoot anyways.

I'm not really sure what you're going to test, as I believe it won't even pass the configure step for gcc.

But if you're willing to add cross compilation, an easy way is to use crosstool-ng (we use it in compiler explorer to build the various cross gcc). But it won't solve the fact that we only support native compiler with existing rustc support 🤷 ç

[powerboat9]

I'm not really sure what you're going to test, as I believe it won't even pass the configure step for gcc.
The configure script succeeds -- I don't think the compile would succeed even without the newlib issue, but its worth a shot.
But if you're willing to add cross compilation, an easy way is to use crosstool-ng (we use it in compiler explorer to build the various cross gcc). But it won't solve the fact that we only support native compiler with existing rustc support 🤷 ç
I'll look into it, might solve the newlib issue.

The big issue we'd have with compiling for a target rustc doesn't support would be the rust runtime libraries we build with cargo, right?