Don't put hermit mutexes in a box.

mkroening · Mukund Lakshman · commit 580dd2e27200 · 2021-08-20T08:19:49.000+01:00
(backport-of: fffa88e) Hermit mutexes are movable.
diff --git a/library/std/src/sys/hermit/mutex.rs b/library/std/src/sys/hermit/mutex.rs
@@ -156,7 +156,7 @@ pub struct Mutex {
     inner: Spinlock<MutexInner>,
 }
 
-pub type MovableMutex = Box<Mutex>;
+pub type MovableMutex = Mutex;
 
 unsafe impl Send for Mutex {}
 unsafe impl Sync for Mutex {}

Original file line number	Diff line number	Diff line change
`@@ -156,7 +156,7 @@ pub struct Mutex {`
`156`	`156`	`inner: Spinlock<MutexInner>,`
`157`	`157`	`}`
`158`	`158`
`159`		`-pub type MovableMutex = Box<Mutex>;`
	`159`	`+pub type MovableMutex = Mutex;`
`160`	`160`
`161`	`161`	`unsafe impl Send for Mutex {}`
`162`	`162`	`unsafe impl Sync for Mutex {}`