avm1: Array.reverse should return itself

core/src/avm1/globals/array.rs

@@ -256,7 +256,8 @@ pub fn reverse<'gc>(
         this.set_array_element(i, values.pop().unwrap(), activation.context.gc_context);
     }
 
-    Ok(Value::Undefined)
+    // Some docs incorrectly say reverse returns Void.
+    Ok(this.into())
 }
 
 pub fn join<'gc>(

core/tests/swfs/avm1/array_trivial/output.txt

@@ -86,6 +86,11 @@ b
 // array
 b,a,c
 
+// array = array.reverse(); array = array.reverse();
+
+// array
+b,a,c
+
 // array.join(" / ")
 b / a / c