Vendor dependencies for 0.3.0 release

vendor/zerocopy/tests/ui-nightly/try_transmute-size-decrease.rs

@@ -0,0 +1,20 @@
+// Copyright 2023 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+include!("../../zerocopy-derive/tests/include.rs");
+
+extern crate zerocopy;
+
+use util::AU16;
+use zerocopy::try_transmute;
+
+// Although this is not a soundness requirement, we currently require that the
+// size of the destination type is not smaller than the size of the source type.
+fn main() {
+    let _decrease_size: Result<u8, _> = try_transmute!(AU16(0));
+}