std: Add Default/IntoIterator/ToOwned to the prelude

This is an implementation of [RFC 1030][rfc] which adds these traits to the
prelude and additionally removes all inherent `into_iter` methods on collections
in favor of the trait implementation (which is now accessible by default).

[rfc]: https://github.com/rust-lang/rfcs/pull/1030

This is technically a breaking change due to the prelude additions and removal
of inherent methods, but it is expected that essentially no code breaks in
practice.

[breaking-change]
Closes #24538

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/sys/common/wtf8.rs b/src/libstd/sys/common/wtf8.rs
index 34a4a773f8e..631e47edb78 100644
--- a/src/libstd/sys/common/wtf8.rs
+++ b/src/libstd/sys/common/wtf8.rs
@@ -35,7 +35,7 @@ use borrow::Cow;
 use cmp;
 use fmt;
 use hash::{Hash, Hasher};
-use iter::{FromIterator, IntoIterator};
+use iter::FromIterator;
 use mem;
 #[allow(deprecated)] // Int
 use num::Int;