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]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libtest/stats.rs b/src/libtest/stats.rs
index 7441b39f35b..41146cded70 100644
--- a/src/libtest/stats.rs
+++ b/src/libtest/stats.rs
@@ -11,7 +11,7 @@
 #![allow(missing_docs)]
 
 use std::collections::hash_map;
-use std::collections::hash_map::{Occupied, Vacant};
+use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::fmt::Show;
 use std::hash::Hash;
 use std::io;