Rollup of 6 pull requests

Cargo.lock

@@ -3663,6 +3663,7 @@ dependencies = [
  "log",
  "rustc",
  "rustc_data_structures",
+ "rustc_error_codes",
  "rustc_errors",
  "rustc_feature",
  "rustc_hir",
@@ -3788,6 +3789,7 @@ dependencies = [
  "rustc_error_codes",
  "rustc_errors",
  "rustc_hir",
+ "rustc_lint",
  "rustc_metadata",
  "rustc_span",
  "syntax",

src/liballoc/tests/lib.rs

@@ -11,6 +11,7 @@
 #![feature(associated_type_bounds)]
 #![feature(binary_heap_into_iter_sorted)]
 #![feature(binary_heap_drain_sorted)]
+#![feature(vec_remove_item)]
 
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};

src/liballoc/vec.rs

@@ -1696,13 +1696,14 @@ impl<T> Vec<T> {
     /// # Examples
     ///
     /// ```
+    /// # #![feature(vec_remove_item)]
     /// let mut vec = vec![1, 2, 3, 1];
     ///
     /// vec.remove_item(&1);
     ///
     /// assert_eq!(vec, vec![2, 3, 1]);
     /// ```
-    #[stable(feature = "vec_remove_item", since = "1.42.0")]
+    #[unstable(feature = "vec_remove_item", reason = "recently added", issue = "40062")]
     pub fn remove_item<V>(&mut self, item: &V) -> Option<T>
     where
         T: PartialEq<V>,

src/libcore/alloc.rs

@@ -64,8 +64,9 @@ impl Layout {
     ///    must not overflow (i.e., the rounded value must be less than
     ///    `usize::MAX`).
     #[stable(feature = "alloc_layout", since = "1.28.0")]
+    #[rustc_const_unstable(feature = "const_alloc_layout", issue = "67521")]
     #[inline]
-    pub fn from_size_align(size: usize, align: usize) -> Result<Self, LayoutErr> {
+    pub const fn from_size_align(size: usize, align: usize) -> Result<Self, LayoutErr> {
         if !align.is_power_of_two() {
             return Err(LayoutErr { private: () });
         }
@@ -106,15 +107,17 @@ impl Layout {
 
     /// The minimum size in bytes for a memory block of this layout.
     #[stable(feature = "alloc_layout", since = "1.28.0")]
+    #[rustc_const_unstable(feature = "const_alloc_layout", issue = "67521")]
     #[inline]
-    pub fn size(&self) -> usize {
+    pub const fn size(&self) -> usize {
         self.size_
     }
 
     /// The minimum byte alignment for a memory block of this layout.
     #[stable(feature = "alloc_layout", since = "1.28.0")]
+    #[rustc_const_unstable(feature = "const_alloc_layout", issue = "67521")]
     #[inline]
-    pub fn align(&self) -> usize {
+    pub const fn align(&self) -> usize {
         self.align_.get()
     }
 
@@ -181,8 +184,9 @@ impl Layout {
     /// address for the whole allocated block of memory. One way to
     /// satisfy this constraint is to ensure `align <= self.align()`.
     #[unstable(feature = "alloc_layout_extra", issue = "55724")]
+    #[rustc_const_unstable(feature = "const_alloc_layout", issue = "67521")]
     #[inline]
-    pub fn padding_needed_for(&self, align: usize) -> usize {
+    pub const fn padding_needed_for(&self, align: usize) -> usize {
         let len = self.size();
 
         // Rounded up value is:

src/libcore/lib.rs

@@ -70,6 +70,7 @@
 #![feature(bound_cloned)]
 #![feature(cfg_target_has_atomic)]
 #![feature(concat_idents)]
+#![feature(const_alloc_layout)]
 #![feature(const_if_match)]
 #![feature(const_panic)]
 #![feature(const_fn_union)]

src/librustc/hir/check_attr.rs

@@ -5,7 +5,6 @@
 //! item.
 
 use crate::hir::map::Map;
-use crate::lint::builtin::UNUSED_ATTRIBUTES;
 use crate::ty::query::Providers;
 use crate::ty::TyCtxt;
 
@@ -16,6 +15,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::DUMMY_HIR_ID;
 use rustc_hir::{self, HirId, Item, ItemKind, TraitItem, TraitItemKind};
+use rustc_session::lint::builtin::UNUSED_ATTRIBUTES;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use syntax::ast::Attribute;

src/librustc/lib.rs

@@ -49,6 +49,7 @@
 #![feature(thread_local)]
 #![feature(trace_macros)]
 #![feature(trusted_len)]
+#![feature(vec_remove_item)]
 #![feature(stmt_expr_attributes)]
 #![feature(integer_atomics)]
 #![feature(test)]
@@ -71,8 +72,6 @@ extern crate rustc_data_structures;
 #[macro_use]
 extern crate log;
 #[macro_use]
-extern crate syntax;
-#[macro_use]
 extern crate smallvec;
 
 #[cfg(test)]