Add #[track_caller] to more panicking Cell functions

Continuation of #74526 Adds the #[track_caller] attribute to almost all panicking Cell functions. The ones that borrow two Cells in their function body are spared, because the panic location helps pinpoint which of the two borrows failed. You'd need to have full debuginfo and backtraces enabled together with column info in order to be able to discern the cases. Column info is only available on non-Windows platforms.
rust-lang · bors · Sep 24, 2020 · Sep 19, 2020 · Sep 19, 2020 · Sep 21, 2020
commit 05c3a2b07dc66fabc874181ce1eebea192cb4b56
diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
@@ -700,6 +700,7 @@ impl<T> RefCell<T> {
     /// ```
     #[inline]
     #[stable(feature = "refcell_replace", since = "1.24.0")]
+    #[track_caller]
     pub fn replace(&self, t: T) -> T {
         mem::replace(&mut *self.borrow_mut(), t)
     }
@@ -722,6 +723,7 @@ impl<T> RefCell<T> {
     /// ```
     #[inline]
     #[stable(feature = "refcell_replace_swap", since = "1.35.0")]
+    #[track_caller]
     pub fn replace_with<F: FnOnce(&mut T) -> T>(&self, f: F) -> T {
         let mut_borrow = &mut *self.borrow_mut();
         let replacement = f(mut_borrow);
@@ -1056,6 +1058,7 @@ impl<T: Clone> Clone for RefCell<T> {
     ///
     /// Panics if the value is currently mutably borrowed.
     #[inline]
+    #[track_caller]
     fn clone(&self) -> RefCell<T> {
         RefCell::new(self.borrow().clone())
     }