Use ptr::Alignment for extra coolness points

compiler/rustc_middle/src/lib.rs

@@ -59,6 +59,7 @@
 #![feature(result_option_inspect)]
 #![feature(const_option)]
 #![feature(trait_alias)]
+#![feature(ptr_alignment_type)]
 #![recursion_limit = "512"]
 #![allow(rustc::potential_query_instability)]
 

compiler/rustc_middle/src/ty/list.rs

@@ -1,5 +1,5 @@
 use crate::arena::Arena;
-use rustc_data_structures::aligned::Aligned;
+use rustc_data_structures::aligned::{align_of, Aligned};
 use rustc_serialize::{Encodable, Encoder};
 use std::alloc::Layout;
 use std::cmp::Ordering;
@@ -203,13 +203,13 @@ unsafe impl<T: Sync> Sync for List<T> {}
 // Layouts of `Equivalent<T>` and `List<T>` are the same, modulo opaque tail,
 // thus aligns of `Equivalent<T>` and `List<T>` must be the same.
 unsafe impl<T> Aligned for List<T> {
-    const ALIGN: usize = {
+    const ALIGN: ptr::Alignment = {
         #[repr(C)]
         struct Equivalent<T> {
             _len: usize,
             _data: [T; 0],
         }
 
-        mem::align_of::<Equivalent<T>>()
+        align_of::<Equivalent<T>>()
     };
 }

compiler/rustc_middle/src/ty/mod.rs

@@ -1626,7 +1626,8 @@ struct ParamTag {
 }
 
 unsafe impl rustc_data_structures::tagged_ptr::Tag for ParamTag {
-    const BITS: usize = 2;
+    const BITS: u32 = 2;
+
     #[inline]
     fn into_usize(self) -> usize {
         match self {
@@ -1636,6 +1637,7 @@ unsafe impl rustc_data_structures::tagged_ptr::Tag for ParamTag {
             Self { reveal: traits::Reveal::All, constness: hir::Constness::Const } => 3,
         }
     }
+
     #[inline]
     unsafe fn from_usize(ptr: usize) -> Self {
         match ptr {