Replace deprecated reverse method usages.

libraries/stdlib/test/collections/CollectionTest.kt

@@ -589,7 +589,7 @@ class CollectionTest {
     }
 
     test fun sortedWith() {
-        val comparator = compareBy<String> { it.toUpperCase().reverse() }
+        val comparator = compareBy<String> { it.toUpperCase().reversed() }
         val data = listOf("cat", "dad", "BAD")
 
         expect(listOf("BAD", "dad", "cat")) { data.sortedWith(comparator) }

libraries/stdlib/test/collections/SequenceTest.kt

@@ -333,7 +333,7 @@ public class SequenceTest {
     }
 
     test fun sortedWith() {
-        val comparator = compareBy { s: String -> s.reverse() }
+        val comparator = compareBy { s: String -> s.reversed() }
         assertEquals(listOf("act", "wast", "test"), sequenceOf("act", "test", "wast").sortedWith(comparator).toList())
     }