Use inline(never) instead of cold

inline(never) is better way to avoid optimizer to inline the function instead of cold.
rust-lang · bors · Sep 16, 2020 · Aug 29, 2020 · Aug 29, 2020 · Sep 2, 2020
commit a80d39041e2d5cd58a846c9ef9e01ee9d691a7ed
diff --git a/library/std/src/thread/local.rs b/library/std/src/thread/local.rs
@@ -424,10 +424,9 @@ pub mod fast {
         // thread_local's, or it is being recursively initialized.
         //
         // Macos: Inlining this function can cause two `tlv_get_addr` calls to
-        // be performed for every call to `Key::get`. The #[cold] hint makes
-        // that less likely.
+        // be performed for every call to `Key::get`.
         // LLVM issue: https://bugs.llvm.org/show_bug.cgi?id=41722
-        #[cold]
+        #[inline(never)]
         unsafe fn try_initialize<F: FnOnce() -> T>(&self, init: F) -> Option<&'static T> {
             if !mem::needs_drop::<T>() || self.try_register_dtor() {
                 Some(self.inner.initialize(init))