Documents int-bounds

Actually, the included definition was also wrong. Closes #2239

Author: JJ

doc/Type/Range.pod6

@@ -243,7 +243,9 @@ Returns C<True> if both end points are C<Int> values.
 
 =head2 method int-bounds
 
-    method int-bounds(Range:D: --> Positional)
+    proto method int-bounds(|)
+    multi method int-bounds()
+    multi method int-bounds($from is rw, $to is rw)
 
 If the C<Range> is an integer range (as indicated by L<is-int|/routine/is-int>), then this
 method returns a list with the first and last value it will iterate over
@@ -253,6 +255,13 @@ Failure if it is not an integer range.
     say (2..5).int-bounds;                            # OUTPUT: «(2 5)␤»
     say (2..^5).int-bounds;                           # OUTPUT: «(2 4)␤»
 
+If called with (writable) arguments, these will take the the values of the
+higher and lower bound:
+
+    (3..5).int-bounds( my $min, my $max);
+    say "$min, $max" ; # OUTPUT: «3, 5␤»
+
+
 =head2 method minmax
 
 Defined as: