Auto merge of #115422 - Zoxc:cache-once-lock, r=cjgillot

Use `OnceLock` for `SingleCache`

This uses `OnceLock` for `SingleCache` instead of `Lock<Option<T>>` so lookups are lock-free.

r? `@cjgillot`

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs
index 2ec509b9118..e82b0f6d496 100644
--- a/compiler/rustc_data_structures/src/sync.rs
+++ b/compiler/rustc_data_structures/src/sync.rs
@@ -273,7 +273,7 @@ cfg_if! {
         pub use std::cell::RefMut as MappedWriteGuard;
         pub use std::cell::RefMut as MappedLockGuard;
 
-        pub use std::cell::OnceCell;
+        pub use std::cell::OnceCell as OnceLock;
 
         use std::cell::RefCell as InnerRwLock;
 
@@ -327,7 +327,7 @@ cfg_if! {
 
         pub use parking_lot::MappedMutexGuard as MappedLockGuard;
 
-        pub use std::sync::OnceLock as OnceCell;
+        pub use std::sync::OnceLock;
 
         pub use std::sync::atomic::{AtomicBool, AtomicUsize, AtomicU32, AtomicU64};