DPC++ daily 2022-05-03

[SYCL][CUDA] Ignore cuda prefetch hint if not supported (#5043)

Specific devices and OS's, like Windows, do not support concurrent managed memory. cudaPrefetchAsync requires concurrent managed access for unified memory. This PR removes the windows error message and replaces it with a check for concurrent managed access. As the SYCL prefetch operation is a hint, this can return a success.

Let me know if there is a preferred error code to throw. Also, if it is best that a user warning is printed to indicate that the hint is being ignored as the device does not support the operation.