add back strict provenance lint

Author: RalfJung

src/lib.rs

@@ -21,6 +21,7 @@
         allocator_api,
         slice_ptr_get,
         maybe_uninit_array_assume_init,
+        strict_provenance_lints
     )
 )]
 #![allow(
@@ -35,6 +36,7 @@
 )]
 #![warn(missing_docs)]
 #![warn(rust_2018_idioms)]
+#![cfg_attr(feature = "nightly", warn(fuzzy_provenance_casts))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 
 /// Default hasher for [`HashMap`] and [`HashSet`].