rollup merge of #18398 : aturon/lint-conventions-2

Conflicts:
	src/libcollections/slice.rs
	src/libcore/failure.rs
	src/libsyntax/parse/token.rs
	src/test/debuginfo/basic-types-mut-globals.rs
	src/test/debuginfo/simple-struct.rs
	src/test/debuginfo/trait-pointers.rs

src/libregex/lib.rs

@@ -370,7 +370,7 @@
 
 #![allow(unknown_features)]
 #![feature(macro_rules, phase, slicing_syntax)]
-#![deny(missing_doc)]
+#![deny(missing_docs)]
 
 #[cfg(test)]
 extern crate "test" as stdtest;