chore: checkpoint before Python removal

vendor/pin-utils/tests/projection.rs

@@ -0,0 +1,27 @@
+use pin_utils::{unsafe_pinned, unsafe_unpinned, pin_mut};
+use std::pin::Pin;
+use std::marker::Unpin;
+
+struct Foo<T1, T2> {
+    field1: T1,
+    field2: T2,
+}
+
+impl<T1, T2> Foo<T1, T2> {
+    unsafe_pinned!(field1: T1);
+    unsafe_unpinned!(field2: T2);
+}
+
+impl<T1: Unpin, T2> Unpin for Foo<T1, T2> {} // Conditional Unpin impl
+
+#[test]
+fn projection() {
+    let foo = Foo { field1: 1, field2: 2 };
+    pin_mut!(foo);
+
+    let x1: Pin<&mut i32> = foo.as_mut().field1();
+    assert_eq!(*x1, 1);
+
+    let x2: &mut i32 = foo.as_mut().field2();
+    assert_eq!(*x2, 2);
+}

vendor/pin-utils/tests/stack_pin.rs

@@ -0,0 +1,21 @@
+#![forbid(unsafe_code)] // pin_mut! is completely safe.
+
+use pin_utils::pin_mut;
+use core::pin::Pin;
+
+#[test]
+fn stack_pin() {
+    struct Foo {}
+    let foo = Foo {};
+    pin_mut!(foo);
+    let _: Pin<&mut Foo> = foo;
+
+    let bar = Foo {};
+    let baz = Foo {};
+    pin_mut!(
+        bar,
+        baz,
+    );
+    let _: Pin<&mut Foo> = bar;
+    let _: Pin<&mut Foo> = baz;
+}