Update Rust to 2019-08-08

rust-toolchain

-nightly-2019-05-10
+nightly-2019-08-08

src/lib.rs

@@ -11,13 +11,9 @@
 #![feature(const_vec_new)]
 #![feature(core_intrinsics)]
 #![feature(global_asm)]
-// FIXME: Add #![feature(maybe_uninit_extra)]
-// FIXME: The following are stable on nightly, remove once redox fork is updated
-#![feature(alloc)]
-#![feature(iter_copied)]
+#![feature(maybe_uninit_extra)]
 #![feature(lang_items)]
 #![feature(linkage)]
-#![feature(maybe_uninit)]
 #![feature(stmt_expr_attributes)]
 #![feature(str_internals)]
 #![feature(thread_local)]