Remove a ton of public reexports

Remove most of the public reexports mentioned in #19253

These are all leftovers from the enum namespacing transition

In particular:

* src/libstd/num/strconv.rs
 * ExponentFormat
 * SignificantDigits
 * SignFormat
* src/libstd/path/windows.rs
 * PathPrefix
* src/libstd/sys/windows/timer.rs
 * Req
* src/libcollections/str.rs
 * MaybeOwned
* src/libstd/collections/hash/map.rs
 * Entry
* src/libstd/collections/hash/table.rs
 * BucketState
* src/libstd/dynamic_lib.rs
 * Rtld
* src/libstd/io/net/ip.rs
 * IpAddr
* src/libstd/os.rs
 * MemoryMapKind
 * MapOption
 * MapError
* src/libstd/sys/common/net.rs
 * SocketStatus
 * InAddr
* src/libstd/sys/unix/timer.rs
 * Req

[breaking-change]

2 files changed, 4 insertions, 3 deletions

diff --git a/src/libcollections/str.rs b/src/libcollections/str.rs
index feec2a216c7..bb03575b3ac 100644
--- a/src/libcollections/str.rs
+++ b/src/libcollections/str.rs
@@ -51,7 +51,7 @@
 
 #![doc(primitive = "str")]
 
-pub use self::MaybeOwned::*;
+use self::MaybeOwned::*;
 use self::RecompositionState::*;
 use self::DecompositionType::*;
 
@@ -842,7 +842,7 @@ mod tests {
     use core::iter::AdditiveIterator;
     use super::{eq_slice, from_utf8, is_utf8, is_utf16, raw};
     use super::truncate_utf16_at_nul;
-    use super::{Owned, Slice};
+    use super::MaybeOwned::{Owned, Slice};
 
     #[test]
     fn test_eq_slice() {
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index bcd1e3b3680..edd96dd683f 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -26,7 +26,8 @@ use core::raw::Slice as RawSlice;
 
 use slice::CloneSliceExt;
 use str;
-use str::{CharRange, CowString, FromStr, StrAllocating, Owned};
+use str::{CharRange, CowString, FromStr, StrAllocating};
+use str::MaybeOwned::Owned;
 use vec::{DerefVec, Vec, as_vec};
 
 /// A growable string stored as a UTF-8 encoded buffer.