message: Interpret system call numbers relative to target architecture
diff: @@ -216,9 +216,9 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a + 'mir>: crate::MiriEvalContextExt<'
  //
  // `libc::syscall(NR_GETRANDOM, buf.as_mut_ptr(), buf.len(), GRND_NONBLOCK)`
  // is called if a `HashMap` is created the regular way (e.g. HashMap<K, V>).
  - match this.read_scalar(args[0])?.to_usize(this)? as i64 {
  + match (this.read_scalar(args[0])?.to_usize(this)? as i64, tcx.data_layout.pointer_size.bits()) {
  // SYS_getrandom on x86_64 and x86 respectively
  - 318 | 355 => {
  + (318, 64) | (355, 32) => {
  let ptr = this.read_scalar(args[1])?.to_ptr()?;
  let len = this.read_scalar(args[2])?.to_usize(this)?;
  @@ -232,7 +232,7 @@ pub trait EvalContextExt<'a, 'mir, 'tcx: 'a + 'mir>: crate::MiriEvalContextExt<'
  this.write_scalar(Scalar::from_uint(len, dest.layout.size), dest)?;
  }
  - id => {
  + (id, _size) => {
  return err!(Unimplemented(
  format!("miri does not support syscall ID {}", id),
  ))
  