Add the "memcpy" doc alias to slice::copy_from_slice

Author: yoshuawuyts

library/core/src/slice/mod.rs

@@ -2724,6 +2724,7 @@ impl<T> [T] {
     ///
     /// [`clone_from_slice`]: #method.clone_from_slice
     /// [`split_at_mut`]: #method.split_at_mut
+    #[doc(alias = "memcpy")]
     #[stable(feature = "copy_from_slice", since = "1.9.0")]
     pub fn copy_from_slice(&mut self, src: &[T])
     where