check that adding infer-outlives requirement to all crates works

src/liballoc/lib.rs

@@ -77,6 +77,7 @@
 #![cfg_attr(not(test), feature(fn_traits))]
 #![cfg_attr(not(test), feature(generator_trait))]
 #![cfg_attr(not(stage0), feature(nll))]
+#![cfg_attr(not(stage0), feature(infer_outlives_requirements))]
 #![cfg_attr(test, feature(test))]
 
 #![feature(allocator_api)]