message: fix field index
diff: @@ -842,7 +842,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  .write_bytes(system_info.ptr, itertools::repeat_n(0, system_info.layout.size.bytes() as usize))?;
  // Set number of processors.
  let dword_size = Size::from_bytes(4);
  - let num_cpus = this.mplace_field(system_info, 5)?;
  + let num_cpus = this.mplace_field(system_info, 6)?;
  this.write_scalar(
  Scalar::from_int(NUM_CPUS, dword_size),
  num_cpus.into(),
  