Work around pre-Rust2021 semantics (array .into_iter() and closure …

…captures).

src/front/spv/mod.rs

@@ -3116,9 +3116,13 @@ impl<I: Iterator<Item = u32>> Parser<I> {
  continuing: loop_continuing_idx,
  break_if: ref mut break_if_slot @ None,
  }] if body_idx == loop_continuing_idx => {
+ // HACK(eddyb) work around pre-Rust2021 closure captures.
+ let ctx_body_for_label = &ctx.body_for_label;
+ let ctx_expressions = &mut ctx.expressions;
+
  // Try both orderings of break-vs-backedge, because
  // SPIR-V is symmetrical here, unlike WGSL `break if`.
- let break_if_cond = [true, false].into_iter().find_map(|true_breaks| {
+ let break_if_cond = [true, false].iter().find_map(|&true_breaks| {
  let (break_candidate, backedge_candidate) = if true_breaks {
  (true_target, false_target)
  } else {
@@ -3136,7 +3140,7 @@ impl<I: Iterator<Item = u32>> Parser<I> {
  // `OpLoopMerge` below (even if it looks weird).
  let backedge_candidate_is_backedge =
  backedge_candidate.merge_info.is_none()
- && ctx.body_for_label.get(&backedge_candidate.label_id)
+ && ctx_body_for_label.get(&backedge_candidate.label_id)
  == Some(&loop_body_idx);
  if !backedge_candidate_is_backedge {
  return None;
@@ -3145,7 +3149,7 @@ impl<I: Iterator<Item = u32>> Parser<I> {
  Some(if true_breaks {
  condition
  } else {
- ctx.expressions.append(
+ ctx_expressions.append(
  crate::Expression::Unary {
  op: crate::UnaryOperator::Not,
  expr: condition,