[NVPTX] Switch front-ends and tests to ptx_kernel cc#120806

AlexMaclean merged 1 commit intollvm:mainllvm/llvm-project:mainfrom

AlexMaclean:dev/amaclean/upstream-switch-to-ccAlexMaclean/llvm-project:dev/amaclean/upstream-switch-to-ccCopy head branch name to clipboard