prefetch intrinsic is a hint to the code generator to insert a prefetch instruction
if supported; otherwise, it is a no-op.
Prefetches have no effect on the behavior of the program but can change its performance
locality argument must be a constant integer and is a temporal locality specifier
ranging from (0) - no locality, to (3) - extremely local keep in cache.
This intrinsic does not have a stable counterpart.