Reorder to keep duplicate checks in sync.

compiler/rustc_abi/src/layout.rs

@@ -744,20 +744,28 @@ pub trait LayoutCalculator {
  for field in only_variant {
  assert!(field.0.is_sized());
 
- if !field.0.is_zst() && !common_non_zst_abi_and_align.is_err() {
+ align = align.max(field.align());
+ size = cmp::max(size, field.size());
+
+ if field.0.is_zst() {
+ // Nothing more to do for ZST fields
+ continue;
+ }
+
+ if let Ok(common) = common_non_zst_abi_and_align {
  // Discard valid range information and allow undef
  let field_abi = field.abi().to_union();
 
- if let Ok(Some((common_abi, common_align))) = &mut common_non_zst_abi_and_align {
- if *common_abi != field_abi {
+ if let Some((common_abi, common_align)) = common {
+ if common_abi != field_abi {
  // Different fields have different ABI: disable opt
  common_non_zst_abi_and_align = Err(AbiMismatch);
  } else {
  // Fields with the same non-Aggregate ABI should also
  // have the same alignment
  if !matches!(common_abi, Abi::Aggregate { .. }) {
  assert_eq!(
- *common_align,
+ common_align,
  field.align().abi,
  "non-Aggregate field with matching ABI but differing alignment"
  );
@@ -768,9 +776,6 @@ pub trait LayoutCalculator {
  common_non_zst_abi_and_align = Ok(Some((field_abi, field.align().abi)));
  }
  }
-
- align = align.max(field.align());
- size = cmp::max(size, field.size());
  }
 
  if let Some(pack) = repr.pack {