std: Stabilize APIs for the 1.8 release

This commit is the result of the FCPs ending for the 1.8 release cycle for both
the libs and the lang suteams. The full list of changes are:

Stabilized

* `braced_empty_structs`
* `augmented_assignments`
* `str::encode_utf16` - renamed from `utf16_units`
* `str::EncodeUtf16` - renamed from `Utf16Units`
* `Ref::map`
* `RefMut::map`
* `ptr::drop_in_place`
* `time::Instant`
* `time::SystemTime`
* `{Instant,SystemTime}::now`
* `{Instant,SystemTime}::duration_since` - renamed from `duration_from_earlier`
* `{Instant,SystemTime}::elapsed`
* Various `Add`/`Sub` impls for `Time` and `SystemTime`
* `SystemTimeError`
* `SystemTimeError::duration`
* Various impls for `SystemTimeError`
* `UNIX_EPOCH`
* `ops::{Add,Sub,Mul,Div,Rem,BitAnd,BitOr,BitXor,Shl,Shr}Assign`

Deprecated

* Scoped TLS (the `scoped_thread_local!` macro)
* `Ref::filter_map`
* `RefMut::filter_map`
* `RwLockReadGuard::map`
* `RwLockWriteGuard::map`
* `Condvar::wait_timeout_with`

Closes #27714
Closes #27715
Closes #27746
Closes #27748
Closes #27908
Closes #29866

src/libstd/thread/mod.rs

@@ -188,6 +188,7 @@ pub use self::local::{LocalKey, LocalKeyState};
            reason = "scoped TLS has yet to have wide enough use to fully \
                      consider stabilizing its interface",
            issue = "27715")]
+#[allow(deprecated)]
 pub use self::scoped_tls::ScopedKey;
 
 #[unstable(feature = "libstd_thread_internals", issue = "0")]

src/libstd/thread/scoped_tls.rs

@@ -41,6 +41,7 @@
 //! ```
 
 #![unstable(feature = "thread_local_internals", issue = "0")]
+#![allow(deprecated)]
 
 #[doc(hidden)]
 pub use self::imp::KeyInner as __KeyInner;
@@ -56,6 +57,8 @@ pub use self::imp::KeyInner as __KeyInner;
            reason = "scoped TLS has yet to have wide enough use to fully consider \
                      stabilizing its interface",
            issue = "27715")]
+#[rustc_deprecated(since = "1.8.0",
+                   reason = "hasn't proven itself over LocalKey")]
 pub struct ScopedKey<T:'static> { inner: fn() -> &'static imp::KeyInner<T> }
 
 /// Declare a new scoped thread local storage key.
@@ -68,6 +71,8 @@ pub struct ScopedKey<T:'static> { inner: fn() -> &'static imp::KeyInner<T> }
 #[unstable(feature = "thread_local_internals",
            reason = "should not be necessary",
            issue = "0")]
+#[rustc_deprecated(since = "1.8.0",
+                   reason = "hasn't proven itself over LocalKey")]
 #[macro_export]
 #[allow_internal_unstable]
 macro_rules! scoped_thread_local {
@@ -85,6 +90,8 @@ macro_rules! scoped_thread_local {
 #[unstable(feature = "thread_local_internals",
            reason = "should not be necessary",
            issue = "0")]
+#[rustc_deprecated(since = "1.8.0",
+                   reason = "hasn't proven itself over LocalKey")]
 #[macro_export]
 #[allow_internal_unstable]
 macro_rules! __scoped_thread_local_inner {
@@ -101,6 +108,8 @@ macro_rules! __scoped_thread_local_inner {
            reason = "scoped TLS has yet to have wide enough use to fully consider \
                      stabilizing its interface",
            issue = "27715")]
+#[rustc_deprecated(since = "1.8.0",
+                   reason = "hasn't proven itself over LocalKey")]
 impl<T> ScopedKey<T> {
     #[doc(hidden)]
     pub const fn new(inner: fn() -> &'static imp::KeyInner<T>) -> ScopedKey<T> {