message: Move stack and stack_mut implementation in Machine to match their position in the trait.
diff: @@ -326,20 +326,6 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'mir, 'tcx> {
  memory_extra.check_alignment
  }
  - #[inline(always)]
  - fn stack<'a>(
  - ecx: &'a InterpCx<'mir, 'tcx, Self>,
  - ) -> &'a [Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>] {
  - &ecx.machine.stack
  - }
  -
  - #[inline(always)]
  - fn stack_mut<'a>(
  - ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
  - ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>> {
  - &mut ecx.machine.stack
  - }
  -
  #[inline(always)]
  fn enforce_validity(ecx: &InterpCx<'mir, 'tcx, Self>) -> bool {
  ecx.machine.validate
  @@ -539,6 +525,20 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'mir, 'tcx> {
  Ok(frame.with_extra(extra))
  }
  + #[inline(always)]
  + fn stack<'a>(
  + ecx: &'a InterpCx<'mir, 'tcx, Self>,
  + ) -> &'a [Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>] {
  + &ecx.machine.stack
  + }
  +
  + #[inline(always)]
  + fn stack_mut<'a>(
  + ecx: &'a mut InterpCx<'mir, 'tcx, Self>,
  + ) -> &'a mut Vec<Frame<'mir, 'tcx, Self::PointerTag, Self::FrameExtra>> {
  + &mut ecx.machine.stack
  + }
  +
  #[inline(always)]
  fn after_stack_push(ecx: &mut InterpCx<'mir, 'tcx, Self>) -> InterpResult<'tcx> {
  if ecx.memory.extra.stacked_borrows.is_some() {
  