Turn on CUDA warnings for unknown stack sizes

These were previously suppressed because they are unavoidable when
calling virtual methods. But we no longer support virtual methods on
devices (it is deprecated).

These warnings can still happen if you have unbounded recursion. But we
would like to avoid unbounded recursion, so we would like to see these
warnings.

Also turned on other nvlink warnings, which include when a recursive
function call means that the compiler cannot figure out the full
stack depth.