message: Do nothing when we try to generate random data of length 0
  This preserves compatibility with programs that pass a null pointer and
  a length of zero to getrandom(), or their platform's equivalent.
diff: @@ -81,6 +81,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  ptr: Scalar<Tag>,
  len: usize,
  ) -> InterpResult<'tcx> {
  + // Some programs pass in a null pointer and a length of 0
  + // to their platform's random-generation function (e.g. getrandom())
  + // on Linux. For compatibility with these programs, we don't perform
  + // any additional checks - it's okay if the pointer is invalid,
  + // since we wouldn't actually be writing to it.
  + if len == 0 {
  + return Ok(())
  + }
  let this = self.eval_context_mut();
  let ptr = match this.memory().check_ptr_access(ptr, Size::from_bytes(len as u64), Align::from_bytes(1).unwrap())? {
  