Auto merge of #118126 - Nilstrieb:rollup-5ogh896, r=Nilstrieb

Rollup of 7 pull requests

Successful merges:

 - #117790 (CFI: Add missing use core::ffi::c_int)
 - #118059 (Explicitly unset $CARGO for compiletest)
 - #118081 (`rustc_ty_utils` cleanups)
 - #118094 (feat: specialize `SpecFromElem` for `()`)
 - #118097 (Update books)
 - #118115 (Fix occurrences of old fn names in comment and tracing)
 - #118121 (`rustc_hir` cleanups)

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_hir/src/arena.rs

@@ -5,7 +5,6 @@ macro_rules! arena_types {
     ($macro:path) => (
         $macro!([
             // HIR types
-            [] hir_krate: rustc_hir::Crate<'tcx>,
             [] asm_template: rustc_ast::InlineAsmTemplatePiece,
             [] attribute: rustc_ast::Attribute,
             [] owner_info: rustc_hir::OwnerInfo<'tcx>,

compiler/rustc_hir/src/def.rs

@@ -13,8 +13,7 @@ use std::array::IntoIter;
 use std::fmt::Debug;
 
 /// Encodes if a `DefKind::Ctor` is the constructor of an enum variant or a struct.
-#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
 pub enum CtorOf {
     /// This `DefKind::Ctor` is a synthesized constructor of a tuple or unit struct.
     Struct,
@@ -23,8 +22,7 @@ pub enum CtorOf {
 }
 
 /// What kind of constructor something is.
-#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
 pub enum CtorKind {
     /// Constructor function automatically created by a tuple struct/variant.
     Fn,
@@ -33,8 +31,7 @@ pub enum CtorKind {
 }
 
 /// An attribute that is not a macro; e.g., `#[inline]` or `#[rustfmt::skip]`.
-#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
 pub enum NonMacroAttrKind {
     /// Single-segment attribute defined by the language (`#[inline]`)
     Builtin(Symbol),
@@ -48,8 +45,7 @@ pub enum NonMacroAttrKind {
 }
 
 /// What kind of definition something is; e.g., `mod` vs `struct`.
-#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
 pub enum DefKind {
     // Type namespace
     Mod,
@@ -299,8 +295,7 @@ impl DefKind {
 /// - the call to `str_to_string` will resolve to [`Res::Def`], with the [`DefId`]
 ///   pointing to the definition of `str_to_string` in the current crate.
 //
-#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
-#[derive(HashStable_Generic)]
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
 pub enum Res<Id = hir::HirId> {
     /// Definition having a unique ID (`DefId`), corresponds to something defined in user code.
     ///
@@ -591,6 +586,8 @@ impl NonMacroAttrKind {
         }
     }
 
+    // Currently trivial, but exists in case a new kind is added in the future whose name starts
+    // with a vowel.
     pub fn article(self) -> &'static str {
         "a"
     }