std: Stabilize APIs for the 1.10 release

This commit applies the FCP decisions made by the libs team for the 1.10 cycle,
including both new stabilizations and deprecations. Specifically, the list of
APIs is:

Stabilized:

* `os::windows::fs::OpenOptionsExt::access_mode`
* `os::windows::fs::OpenOptionsExt::share_mode`
* `os::windows::fs::OpenOptionsExt::custom_flags`
* `os::windows::fs::OpenOptionsExt::attributes`
* `os::windows::fs::OpenOptionsExt::security_qos_flags`
* `os::unix::fs::OpenOptionsExt::custom_flags`
* `sync::Weak::new`
* `Default for sync::Weak`
* `panic::set_hook`
* `panic::take_hook`
* `panic::PanicInfo`
* `panic::PanicInfo::payload`
* `panic::PanicInfo::location`
* `panic::Location`
* `panic::Location::file`
* `panic::Location::line`
* `ffi::CStr::from_bytes_with_nul`
* `ffi::CStr::from_bytes_with_nul_unchecked`
* `ffi::FromBytesWithNulError`
* `fs::Metadata::modified`
* `fs::Metadata::accessed`
* `fs::Metadata::created`
* `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange`
* `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange_weak`
* `collections::{btree,hash}_map::{Occupied,Vacant,}Entry::key`
* `os::unix::net::{UnixStream, UnixListener, UnixDatagram, SocketAddr}`
* `SocketAddr::is_unnamed`
* `SocketAddr::as_pathname`
* `UnixStream::connect`
* `UnixStream::pair`
* `UnixStream::try_clone`
* `UnixStream::local_addr`
* `UnixStream::peer_addr`
* `UnixStream::set_read_timeout`
* `UnixStream::set_write_timeout`
* `UnixStream::read_timeout`
* `UnixStream::write_Timeout`
* `UnixStream::set_nonblocking`
* `UnixStream::take_error`
* `UnixStream::shutdown`
* Read/Write/RawFd impls for `UnixStream`
* `UnixListener::bind`
* `UnixListener::accept`
* `UnixListener::try_clone`
* `UnixListener::local_addr`
* `UnixListener::set_nonblocking`
* `UnixListener::take_error`
* `UnixListener::incoming`
* RawFd impls for `UnixListener`
* `UnixDatagram::bind`
* `UnixDatagram::unbound`
* `UnixDatagram::pair`
* `UnixDatagram::connect`
* `UnixDatagram::try_clone`
* `UnixDatagram::local_addr`
* `UnixDatagram::peer_addr`
* `UnixDatagram::recv_from`
* `UnixDatagram::recv`
* `UnixDatagram::send_to`
* `UnixDatagram::send`
* `UnixDatagram::set_read_timeout`
* `UnixDatagram::set_write_timeout`
* `UnixDatagram::read_timeout`
* `UnixDatagram::write_timeout`
* `UnixDatagram::set_nonblocking`
* `UnixDatagram::take_error`
* `UnixDatagram::shutdown`
* RawFd impls for `UnixDatagram`
* `{BTree,Hash}Map::values_mut`
* `<[_]>::binary_search_by_key`

Deprecated:

* `StaticCondvar` - this, and all other static synchronization primitives
                    below, are usable today through the lazy-static crate on
                    stable Rust today. Additionally, we'd like the non-static
                    versions to be directly usable in a static context one day,
                    so they're unlikely to be the final forms of the APIs in any
                    case.
* `CONDVAR_INIT`
* `StaticMutex`
* `MUTEX_INIT`
* `StaticRwLock`
* `RWLOCK_INIT`
* `iter::Peekable::is_empty`

Closes #27717
Closes #27720
cc #27784 (but encode methods still exist)
Closes #30014
Closes #30425
Closes #30449
Closes #31190
Closes #31399
Closes #31767
Closes #32111
Closes #32281
Closes #32312
Closes #32551
Closes #33018

2 files changed, 7 insertions, 4 deletions

diff --git a/src/librustc_back/dynamic_lib.rs b/src/librustc_back/dynamic_lib.rs
index 2f86262afbe..38e60060925 100644
--- a/src/librustc_back/dynamic_lib.rs
+++ b/src/librustc_back/dynamic_lib.rs
@@ -189,12 +189,16 @@ mod dl {
     pub fn check_for_errors_in<T, F>(f: F) -> Result<T, String> where
         F: FnOnce() -> T,
     {
-        use std::sync::StaticMutex;
-        static LOCK: StaticMutex = StaticMutex::new();
+        use std::sync::{Mutex, Once, ONCE_INIT};
+        static INIT: Once = ONCE_INIT;
+        static mut LOCK: *mut Mutex<()> = 0 as *mut _;
         unsafe {
+            INIT.call_once(|| {
+                LOCK = Box::into_raw(Box::new(Mutex::new(())));
+            });
             // dlerror isn't thread safe, so we need to lock around this entire
             // sequence
-            let _guard = LOCK.lock();
+            let _guard = (*LOCK).lock();
             let _old_error = libc::dlerror();
 
             let result = f();
diff --git a/src/librustc_back/lib.rs b/src/librustc_back/lib.rs
index 67b11a930d6..6a7bc51d15a 100644
--- a/src/librustc_back/lib.rs
+++ b/src/librustc_back/lib.rs
@@ -38,7 +38,6 @@
 #![feature(staged_api)]
 #![feature(step_by)]
 #![feature(question_mark)]
-#![cfg_attr(unix, feature(static_mutex))]
 #![cfg_attr(test, feature(test, rand))]
 
 extern crate syntax;