Only run find_first/last octillion on 64-bit targets

tests/octillion.rs

@@ -33,19 +33,25 @@ fn octillion_flat() -> impl ParallelIterator<Item = u128> {
         })
 }
 
+// NOTE: `find_first` and `find_last` currently take too long on 32-bit targets,
+// because the `AtomicUsize` match position has much too limited resolution.
+
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_first_octillion() {
     let x = octillion().find_first(|_| true);
     assert_eq!(x, Some(0));
 }
 
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_first_octillion_inclusive() {
     let x = octillion_inclusive().find_first(|_| true);
     assert_eq!(x, Some(0));
 }
 
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_first_octillion_flat() {
     let x = octillion_flat().find_first(|_| true);
     assert_eq!(x, Some(0));
@@ -62,6 +68,7 @@ fn two_threads<F: Send + FnOnce() -> R, R: Send>(f: F) -> R {
 }
 
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_last_octillion() {
     // It would be nice if `find_last` could prioritize the later splits,
     // basically flipping the `join` args, without needing indexed `rev`.
@@ -71,12 +78,14 @@ fn find_last_octillion() {
 }
 
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_last_octillion_inclusive() {
     let x = two_threads(|| octillion_inclusive().find_last(|_| true));
     assert_eq!(x, Some(OCTILLION));
 }
 
 #[test]
+#[cfg_attr(not(target_pointer_width = "64"), ignore)]
 fn find_last_octillion_flat() {
     let x = two_threads(|| octillion_flat().find_last(|_| true));
     assert_eq!(x, Some(OCTILLION - 1));