Update tests following rust-lang#89825

Author: Jules Bertholet

library/alloc/tests/slice.rs

@@ -1023,7 +1023,7 @@ fn test_rsplitator_inclusive() {
     assert_eq!(xs.rsplit_inclusive(|_| true).collect::<Vec<_>>(), splits);
 
     let xs: &[i32] = &[];
-    let splits: &[&[i32]] = &[&[]];
+    let splits: &[&[i32]] = &[];
     assert_eq!(xs.rsplit_inclusive(|x| *x == 5).collect::<Vec<_>>(), splits);
 }
 
@@ -1043,7 +1043,7 @@ fn test_rsplitator_inclusive_reverse() {
     assert_eq!(xs.rsplit_inclusive(|_| true).rev().collect::<Vec<&[i32]>>(), splits);
 
     let xs: &[i32] = &[];
-    let splits: &[&[i32]] = &[&[]];
+    let splits: &[&[i32]] = &[];
     assert_eq!(xs.rsplit_inclusive(|x| *x == 5).rev().collect::<Vec<&[i32]>>(), splits);
 }
 
@@ -1063,7 +1063,7 @@ fn test_rsplitator_mut_inclusive() {
     assert_eq!(xs.rsplit_inclusive_mut(|_| true).collect::<Vec<_>>(), splits);
 
     let xs: &mut [i32] = &mut [];
-    let splits: &[&[i32]] = &[&[]];
+    let splits: &[&[i32]] = &[];
     assert_eq!(xs.rsplit_inclusive_mut(|x| *x == 5).collect::<Vec<_>>(), splits);
 }
 
@@ -1083,7 +1083,7 @@ fn test_rsplitator_mut_inclusive_reverse() {
     assert_eq!(xs.rsplit_inclusive_mut(|_| true).rev().collect::<Vec<_>>(), splits);
 
     let xs: &mut [i32] = &mut [];
-    let splits: &[&[i32]] = &[&[]];
+    let splits: &[&[i32]] = &[];
     assert_eq!(xs.rsplit_inclusive_mut(|x| *x == 5).rev().collect::<Vec<_>>(), splits);
 }