Use #[track_caller] to make panic in Iterator::array_chunks nicer

Author: WaffleLapkin

library/core/src/iter/adapters/array_chunks.rs

@@ -24,6 +24,7 @@ impl<I, const N: usize> ArrayChunks<I, N>
 where
     I: Iterator,
 {
+    #[track_caller]
     pub(in crate::iter) fn new(iter: I) -> Self {
         assert!(N != 0, "chunk size must be non-zero");
         Self { iter: iter.fuse(), remainder: None }

library/core/src/iter/traits/iterator.rs

@@ -3350,6 +3350,7 @@ pub trait Iterator {
     ///     assert_eq!(x + y + z, 4);
     /// }
     /// ```
+    #[track_caller]
     #[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "none")]
     fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
     where