Vendor dependencies for 0.3.0 release

vendor/pin-project/tests/ui/unstable-features/negative_impls.rs

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+#![feature(negative_impls)]
+
+// https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/design.20meeting.3A.20backlog.20bonanza/near/269471299
+// https://github.com/taiki-e/pin-project/issues/340
+
+#[pin_project::pin_project]
+struct Foo<Pinned, Unpinned> {
+    #[pin]
+    pinned: Pinned,
+    unpinned: Unpinned,
+}
+
+struct MyPhantomPinned {}
+impl !Unpin for MyPhantomPinned {}
+impl Unpin for Foo<MyPhantomPinned, ()> {}
+
+fn is_unpin<T: Unpin>() {}
+
+fn main() {
+    is_unpin::<Foo<MyPhantomPinned, ()>>()
+}