Vendor dependencies

Let's see how I like this workflow.

vendor/pin-project-lite/tests/ui/pinned_drop/call-drop-inner.rs

@@ -0,0 +1,17 @@
+use pin_project_lite::pin_project;
+
+pin_project! {
+    pub struct S {
+        #[pin]
+        field: u8,
+    }
+    impl PinnedDrop for S {
+        fn drop(this: Pin<&mut Self>) {
+            __drop_inner(this);
+        }
+    }
+}
+
+fn main() {
+    let _x = S { field: 0 };
+}