Enable extra warnings required by rust-lang/rust

crates/vfs-notify/src/lib.rs

@@ -6,6 +6,9 @@
 //!
 //! Hopefully, one day a reliable file watching/walking crate appears on
 //! crates.io, and we can reduce this to trivial glue code.
+
+#![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
+
 use std::fs;
 
 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};