Once:new() is const-stable since Rust 1.24

... so stop using `ONCE_INIT` which is deprecated in 1.37.

Author: cuviper

rayon-core/src/registry.rs

@@ -19,7 +19,7 @@ use std::ptr;
 #[allow(deprecated)]
 use std::sync::atomic::ATOMIC_USIZE_INIT;
 use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::{Arc, Once, ONCE_INIT};
+use std::sync::{Arc, Once};
 use std::thread;
 use std::usize;
 use unwind;
@@ -161,7 +161,7 @@ pub(super) struct Registry {
 /// Initialization
 
 static mut THE_REGISTRY: Option<&'static Arc<Registry>> = None;
-static THE_REGISTRY_SET: Once = ONCE_INIT;
+static THE_REGISTRY_SET: Once = Once::new();
 
 /// Starts the worker threads (if that has not already happened). If
 /// initialization has not already occurred, use the default