rollup merge of #20607: nrc/kinds

Conflicts:
	src/libcore/array.rs
	src/libcore/cell.rs
	src/libcore/prelude.rs
	src/libstd/path/posix.rs
	src/libstd/prelude/v1.rs
	src/test/compile-fail/dst-sized-trait-param.rs

src/liballoc/arc.rs

@@ -74,7 +74,7 @@ use core::clone::Clone;
 use core::fmt::{self, Show};
 use core::cmp::{Eq, Ord, PartialEq, PartialOrd, Ordering};
 use core::default::Default;
-use core::kinds::{Sync, Send};
+use core::marker::{Sync, Send};
 use core::mem::{min_align_of, size_of, drop};
 use core::mem;
 use core::nonzero::NonZero;