Enable extra warnings required by rust-lang/rust

crates/project-model/src/lib.rs

@@ -15,6 +15,8 @@
 //!   procedural macros).
 //! * Lowering of concrete model to a [`base_db::CrateGraph`]
 
+#![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
+
 mod manifest_path;
 mod cargo_workspace;
 mod cfg_flag;