[UR][HIP] Unbundle hip conformance test binaries

[RossBrunton]

The binaries used for conformance testing on hip are generated using
SYCL programs which output a "bundled object" rather than a raw amdhsa
binary. This unbundles the objects so that the HIP conformance tests are
given the raw binaries.

[RossBrunton]

@intel/llvm-reviewers-cuda Apologies if you aren't the right team for this, but could I get eyes on this? There seems to be two main types of binaries that the hip backend can accept: An "offload bundle" and a raw elf. Offload doesn't seem to support the "offload bundle", so this change switches to using the raw elf for testing.

If I understand correctly, there should be no real difference between the actual binary data or behaviour.

[npmiller]

Yes, that's the right team.

The change looks good to me, although I believe SYCL is passing the "offload bundle" version to the ur adapters at the moment.

Wouldn't the proper fix be to make offload also support that, what do you think? But I don't really know how offload works currently, so I'm happy to go with that for now if it makes more sense.

[RossBrunton]

@npmiller Perhaps, yeah. But I think that would require a lot of work either on the AMD or (more likely) liboffload's end. I think such a thing should probably be done as a separate task and with a proper design. I'd rather just have this change for now and look at "offload bundle" support later.

[npmiller]

After further discussions: offload for AMD is currently based on HSA so it can't easily support the HIP bundles. We may still want to support them in the future but this is a good workaround in the meantime.

[RossBrunton]

Closing this: While it would have made sense as a temporary workaround, adding hip bundle support to the offload UR backend was easier than expected. Since SYCL provides hip bundles anyway, it's worth just merging that instead.