[llvm] [offload][SYCL] Add SYCL Module splitting. (PR #131347)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

Yes exactly. If the pass is only used with a "SYCLTargetMachine" then this SplitModule impl should live right next to that, and use the module splitting override hook from TargetMachine similarly to how AMDGPU does it.

If it can be used in combination with any other TargetMachine then this is the right approach (though I wish we had a better one).

https://github.com/llvm/llvm-project/pull/131347