[clang] [llvm] [Driver][clang-linker-wrapper] Add initial support for OpenMP offloading to generic SPIR-V (PR #120145)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> @jhuber6 Thanks, if you don't think we need any more reviews do you mind merging? I still don't have push (working on it). If not, could you please ping other reviewers? Thx

Sure, what's left for this to work? I'm probably going to be messing around with the OpenMP 'DeviceRTL' more, likely killing off the 'fatbinary' and just using the per-target runtime dir stuff. I'm going to assume this wouldn't work well with SPIR-V since they don't have a consistent toolchain set up yet. What's we'd need is something like this.
```
# <install>/lib/spirv64-unknown-intel/libomp.a
$ clang --target=spirv64-unknown-intel -lomp -v
spirv-linker-wrapper -lomp
```

https://github.com/llvm/llvm-project/pull/120145