Add a regression test for issue-68951

Author: JohnTitor

src/test/ui/issues/issue-68951.rs

@@ -0,0 +1,9 @@
+// check-pass
+
+fn main() {
+    let array = [0x42u8; 10];
+    for b in &array {
+        let lo = b & 0xf;
+        let hi = (b >> 4) & 0xf;
+    }
+}