Work around buggy rust-analyzer behavior

As far as I can tell there is still no way to block it from
autoimporting the private macros here.

Author: dtolnay

src/lib.rs

@@ -376,6 +376,7 @@ extern crate std;
 // Not public API. Used from macro-generated code.
 #[doc(hidden)]
 pub mod __private {
+    #[doc(hidden)]
     pub use alloc::vec;
 }