[llvm] [SPIRV] Change how to detect OpenCL/Vulkan Env and update tests accordingly. (PR #129689)

[Vyacheslav Levytskyy via llvm-commits]

VyacheslavLevytskyy wrote:

I'm afraid, this looks fragile with regards to the triple. Triples of kinds, for instance, "spirv64-unknown-unknown" and "spirv64v1.6-unknown-unknown" are massively in use. If a user needs now to apply "-opencl" everywhere to be recognized as the user of the Compute flavor of SPIR-V, I expect that pretty much everything will start to fail after this change. Probably we need a way that doesn't require updating the whole Compute's set of test cases, this is the only guarantee that SYCL, Intel's XPU backend for Triton, etc. will not notice the internal change in the SPIR-V backend.

https://github.com/llvm/llvm-project/pull/129689