Now all we need is a way to run CUDA code on OpenCL
Good luck with all the languages supported by CUDA.
On some OpenCL implementations (as in, the ones supporting the SPIR-V OpenCL profile instead of just OpenCL C), this is possible.
Intel has a cleaned up variant of OpenCL for the purpose of running SPIR-V binaries called oneAPI L0, and Zluda can run on top of it. https://github.com/vosen/ZLUDA
AMD used to support SPIR in their driver, but they removed support for that in 2018. As such, you won’t get anything useful out of that one on AMD GPUs.