Move /src/test to /tests

tests/ui/iterators/skip-count-overflow.rs

@@ -0,0 +1,8 @@
+// run-pass
+// only-32bit too impatient for 2⁶⁴ items
+// compile-flags: -C overflow-checks -C opt-level=3
+
+fn main() {
+    let i = (0..usize::MAX).chain(0..10).skip(usize::MAX);
+    assert_eq!(i.count(), 10);
+}