[llvm] [SPIR-V] Enable structurizer for kernel environment (PR #166079)

[Dmitry Sidorov via llvm-commits]

MrSidims wrote:

> Is OpenCL going to requires SCFG?

Not really, yet (AFAIK) it's the only way to preserve unroll and other loop metadata.

https://github.com/llvm/llvm-project/pull/166079