remove non-run-fail tests

Author: matthew-piziak

src/libcoretest/iter.rs

@@ -915,20 +915,6 @@ fn test_range_step() {
     assert_eq!((isize::MIN..isize::MAX).step_by(1).size_hint(), (usize::MAX, Some(usize::MAX)));
 }
 
-#[test]
-#[should_panic]
-fn test_range_overflow_unsigned() {
-    let mut it = u8::MAX..;
-    it.next();
-}
-
-#[test]
-#[should_panic]
-fn test_range_overflow_signed() {
-    let mut it = i8::MAX..;
-    it.next();
-}
-
 #[test]
 fn test_repeat() {
     let mut it = repeat(42);