[clang] [llvm] Make OpenCL an OSType rather than an EnvironmentType. (PR #170297)

[Juan Manuel Martinez Caamaño via cfe-commits]

https://github.com/jmmartinez approved this pull request.

Hello,
The change makes sense to me.

I find the `opencl` naming a bit odd, but do not have something better to suggest.

I find it odd in the sense that `opencl` is not really an OS.

I'm also wondering how this could eventually compose with other targets. For example, if I'm compiling for `amd`, we could use `amdgcn-amd-opencl` instead of `--amdhsa`? and would that enable some simplification somewhere? Are other targets communicating some OpenCL specific information in the IR through other means, like metadata, attributes... that we could replace?

I was thinking about `-compute` but what does that even mean... It obscures the relationship between the target and the associated spec.

https://github.com/llvm/llvm-project/pull/170297