chore: checkpoint before Python removal

vendor/pin-project/tests/ui/pin_project/unaligned_references.rs

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Refs: https://github.com/rust-lang/rust/issues/82523
+
+#[repr(packed)]
+struct Packed {
+    f: u32,
+}
+
+#[repr(packed(2))]
+struct PackedN {
+    f: u32,
+}
+
+fn main() {
+    let a = Packed { f: 1 };
+    let _ = &a.f; //~ ERROR reference to packed field is unaligned
+
+    let b = PackedN { f: 1 };
+    let _ = &b.f; //~ ERROR reference to packed field is unaligned
+}