Reapply [Offload][lit] Link against SPIR-V DeviceRTL if present (#180231)
I'll merge this at the same time as some llvm-zorg changes that start
building the DeviceRTL.
We only see one new test passing because everything still fails because
of the issue described in
https://github.com/llvm/llvm-project/pull/178980
Once a fix for that issue is merged we will see many new passes.