Rename never_type_impls gate to never_type

src/libcore/cmp.rs

@@ -880,24 +880,24 @@ fn cmp(&self, other: &bool) -> Ordering {
 
     ord_impl! { char usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 }
 
-    #[unstable(feature = "never_type_impls", issue = "35121")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl PartialEq for ! {
         fn eq(&self, _: &!) -> bool {
             *self
         }
     }
 
-    #[unstable(feature = "never_type_impls", issue = "35121")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Eq for ! {}
 
-    #[unstable(feature = "never_type_impls", issue = "35121")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl PartialOrd for ! {
         fn partial_cmp(&self, _: &!) -> Option<Ordering> {
             *self
         }
     }
 
-    #[unstable(feature = "never_type_impls", issue = "35121")]
+    #[unstable(feature = "never_type", issue = "35121")]
     impl Ord for ! {
         fn cmp(&self, _: &!) -> Ordering {
             *self

src/libcore/fmt/mod.rs

@@ -1546,14 +1546,14 @@ fn fmt(&self, f: &mut Formatter) -> Result { $tr::fmt(&**self, f) }
 
 fmt_refs! { Debug, Display, Octal, Binary, LowerHex, UpperHex, LowerExp, UpperExp }
 
-#[unstable(feature = "never_type_impls", issue = "35121")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Debug for ! {
     fn fmt(&self, _: &mut Formatter) -> Result {
         *self
     }
 }
 
-#[unstable(feature = "never_type_impls", issue = "35121")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Display for ! {
     fn fmt(&self, _: &mut Formatter) -> Result {
         *self

src/libstd/error.rs

@@ -234,7 +234,7 @@ fn from(err: Cow<'a, str>) -> Box<Error> {
     }
 }
 
-#[unstable(feature = "never_type_impls", issue = "35121")]
+#[unstable(feature = "never_type", issue = "35121")]
 impl Error for ! {
     fn description(&self) -> &str { *self }
 }

src/libstd/primitive_docs.rs

@@ -192,7 +192,7 @@ mod prim_bool { }
 /// [`Default`]: default/trait.Default.html
 /// [`default()`]: default/trait.Default.html#tymethod.default
 ///
-#[unstable(feature = "never_type_impls", issue = "35121")]
+#[unstable(feature = "never_type", issue = "35121")]
 mod prim_never { }
 
 #[doc(primitive = "char")]