Auto merge of #128959 - matthiaskrgr:rollup-6jdqi3l, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #120314 (core: optimise Debug impl for ascii::Char)
 - #128536 (Preliminary cleanup of `WitnessPat` hoisting/printing)
 - #128592 (Promote aarch64-apple-darwin to Tier 1)
 - #128762 (Use more slice patterns inside the compiler)
 - #128875 (rm `import.used`)
 - #128882 (make LocalWaker::will_wake consistent with Waker::will_wake)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_data_structures/src/transitive_relation.rs b/compiler/rustc_data_structures/src/transitive_relation.rs
index 26b00e0af3a..e81ebb9a4be 100644
--- a/compiler/rustc_data_structures/src/transitive_relation.rs
+++ b/compiler/rustc_data_structures/src/transitive_relation.rs
@@ -203,9 +203,9 @@ impl<T: Eq + Hash + Copy> TransitiveRelation<T> {
     /// exists). See `postdom_upper_bound` for details.
     pub fn mutual_immediate_postdominator(&self, mut mubs: Vec<T>) -> Option<T> {
         loop {
-            match mubs.len() {
-                0 => return None,
-                1 => return Some(mubs[0]),
+            match mubs[..] {
+                [] => return None,
+                [mub] => return Some(mub),
                 _ => {
                     let m = mubs.pop().unwrap();
                     let n = mubs.pop().unwrap();