remove NoSendItem and NoSyncItem

Author: Jorge Aparicio

src/doc/reference.md

@@ -2377,10 +2377,6 @@ These types help drive the compiler's analysis
   : ___Needs filling in___
 * `no_copy_bound`
   : This type does not implement "copy", even if eligible.
-* `no_send_bound`
-  : This type does not implement "send", even if eligible.
-* `no_sync_bound`
-  : This type does not implement "sync", even if eligible.
 * `eh_personality`
   : ___Needs filling in___
 * `exchange_free`

src/doc/trpl/unsafe.md

@@ -707,7 +707,7 @@ Other features provided by lang items include:
   various kinds; lang items `send`, `sync` and `copy`.
 - the marker types and variance indicators found in
   `std::marker`; lang items `covariant_type`,
-  `contravariant_lifetime`, `no_sync_bound`, etc.
+  `contravariant_lifetime`, etc.
 
 Lang items are loaded lazily by the compiler; e.g. if one never uses
 `Box` then there is no need to define functions for `exchange_malloc`

src/librustc/middle/lang_items.rs

@@ -320,9 +320,7 @@ lets_do_this! {
     ContravariantLifetimeItem,       "contravariant_lifetime",  contravariant_lifetime;
     InvariantLifetimeItem,           "invariant_lifetime",      invariant_lifetime;
 
-    NoSendItem,                      "no_send_bound",           no_send_bound;
     NoCopyItem,                      "no_copy_bound",           no_copy_bound;
-    NoSyncItem,                      "no_sync_bound",           no_sync_bound;
     ManagedItem,                     "managed_bound",           managed_bound;
 
     NonZeroItem,                     "non_zero",                non_zero;

src/librustc/middle/traits/select.rs

@@ -1554,10 +1554,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             let tcx = this.tcx();
             match bound {
                 ty::BoundSend => {
-                    if
-                        Some(def_id) == tcx.lang_items.no_send_bound() ||
-                        Some(def_id) == tcx.lang_items.managed_bound()
-                    {
+                    if Some(def_id) == tcx.lang_items.managed_bound() {
                         return Err(Unimplemented)
                     }
                 }
@@ -1568,7 +1565,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
                 ty::BoundSync => {
                     if
-                        Some(def_id) == tcx.lang_items.no_sync_bound() ||
                         Some(def_id) == tcx.lang_items.managed_bound() ||
                         Some(def_id) == tcx.lang_items.unsafe_type()
                     {