rollup merge of #20754: nikomatsakis/int-feature

Conflicts:
	src/test/compile-fail/borrowck-move-out-of-overloaded-auto-deref.rs
	src/test/compile-fail/issue-2590.rs
	src/test/compile-fail/lint-stability.rs
	src/test/compile-fail/slice-mut-2.rs
	src/test/compile-fail/std-uncopyable-atomics.rs

src/libfmt_macros/lib.rs

@@ -25,6 +25,7 @@
        html_playground_url = "http://play.rust-lang.org/")]
 
 #![feature(slicing_syntax)]
+#![allow(unknown_features)] #![feature(int_uint)]
 
 pub use self::Piece::*;
 pub use self::Position::*;