Rollup merge of rust-lang#96050 - oli-obk:deaggregator_cleanup, r=Ral…

…fJung

Remove some now-dead code that was only relevant before deaggregation.

The code was broken anyway, if the deaggregator is disabled, it would have ICEd on any non-enum Adt

r? ``@RalfJung``

compiler/rustc_const_eval/src/interpret/step.rs

@@ -196,27 +196,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
  self.write_immediate(*val, &dest)?;
  }
 
- Aggregate(ref kind, ref operands) => {
- // active_field_index is for union initialization.
- let (dest, active_field_index) = match **kind {
- mir::AggregateKind::Adt(adt_did, variant_index, _, _, active_field_index) => {
- self.write_discriminant(variant_index, &dest)?;
- if self.tcx.adt_def(adt_did).is_enum() {
- assert!(active_field_index.is_none());
- (self.place_downcast(&dest, variant_index)?, None)
- } else {
- if active_field_index.is_some() {
- assert_eq!(operands.len(), 1);
- }
- (dest, active_field_index)
- }
- }
- _ => (dest, None),
- };
+ Aggregate(box ref kind, ref operands) => {
+ assert!(matches!(kind, mir::AggregateKind::Array(..)));
 
- for (i, operand) in operands.iter().enumerate() {
+ for (field_index, operand) in operands.iter().enumerate() {
  let op = self.eval_operand(operand, None)?;
- let field_index = active_field_index.unwrap_or(i);
  let field_dest = self.place_field(&dest, field_index)?;
  self.copy_op(&op, &field_dest)?;
  }