document panic behavior of Vec::resize and Vec::resize_with

Author: jogru0

Diff for: library/alloc/src/vec/mod.rs

@@ -2803,6 +2803,10 @@ impl<T, A: Allocator> Vec<T, A> {
     /// want to use the [`Default`] trait to generate values, you can
     /// pass [`Default::default`] as the second argument.
     ///
+    /// # Panics
+    ///
+    /// Panics if the new capacity exceeds `isize::MAX` _bytes_.
+    ///
     /// # Examples
     ///
     /// ```
@@ -3010,6 +3014,10 @@ impl<T: Clone, A: Allocator> Vec<T, A> {
     /// [`Clone`]), use [`Vec::resize_with`].
     /// If you only need to resize to a smaller size, use [`Vec::truncate`].
     ///
+    /// # Panics
+    ///
+    /// Panics if the new capacity exceeds `isize::MAX` _bytes_.
+    ///
     /// # Examples
     ///
     /// ```