OpenCL was added as an `EnvironmentType` in https://github.com/llvm/llvm-project/pull/78655, but there is no explanation as to why it was added as such, even after explicitly asking in the PR (https://github.com/llvm/llvm-project/pull/78655#issuecomment-2743162853). This PR makes it an `OSType` instead, which feels more natural, and updates tests accordingly. --------- Co-authored-by: Marcos Maronas <marcos.maronas@intel.com>