Auto merge of #139336 - matthiaskrgr:rollup-zsi8pgf, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #138017 (Tighten up assignment operator representations.)
 - #138462 (Dedup `&mut *` reborrow suggestion in loops)
 - #138610 (impl !PartialOrd for HirId)
 - #138767 (Allow boolean literals in `check-cfg`)
 - #139068 (io: Avoid marking some bytes as uninit)
 - #139255 (Remove unused variables generated in merged doctests)
 - #139270 (Add a mailmap entry for myself)
 - #139303 (Put Noratrieb on vacation)
 - #139312 (add Marco Ieni to mailmap)

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

Author: bors

.mailmap

@@ -276,7 +276,7 @@ Jacob Greenfield <xales@naveria.com>
 Jacob Pratt <jacob@jhpratt.dev> <the.z.cuber@gmail.com>
 Jacob Pratt <jacob@jhpratt.dev> <jacopratt@tesla.com>
 Jake Goulding <jake.goulding@integer32.com>
-Jake Goulding <jake.goulding@integer32.com> <jake.goulding@gmail.com> 
+Jake Goulding <jake.goulding@integer32.com> <jake.goulding@gmail.com>
 Jake Goulding <jake.goulding@integer32.com> <shepmaster@mac.com>
 Jake Vossen <jake@vossen.dev>
 Jakob Degen <jakob.e.degen@gmail.com> <jakob@degen.com>
@@ -412,6 +412,7 @@ Malo Jaffré <jaffre.malo@gmail.com>
 Manish Goregaokar <manishsmail@gmail.com>
 Mara Bos <m-ou.se@m-ou.se>
 Marcell Pardavi <marcell.pardavi@gmail.com>
+Marco Ieni <11428655+MarcoIeni@users.noreply.github.com>
 Marcus Klaas de Vries <mail@marcusklaas.nl>
 Margaret Meyerhofer <mmeyerho@andrew.cmu.edu> <mmeyerho@andrew>
 Mark Mansi <markm@cs.wisc.edu>
@@ -565,6 +566,9 @@ Robert Habermeier <rphmeier@gmail.com>
 Robert Millar <robert.millar@cantab.net>
 Roc Yu <rocyu@protonmail.com>
 Rohit Joshi <rohitjoshi@users.noreply.github.com> Rohit Joshi <rohit.joshi@capitalone.com>
+Ross Smyth <18294397+RossSmyth@users.noreply.github.com>
+Ross Smyth <18294397+RossSmyth@users.noreply.github.com> <crs2017@gmail.com>
+Ross Smyth <18294397+RossSmyth@users.noreply.github.com> <rsmyth@electrocraft.com>
 Roxane Fruytier <roxane.fruytier@hotmail.com>
 Rui <xiongmao86dev@sina.com>
 Russell Johnston <rpjohnst@gmail.com>

compiler/rustc_ast/src/ast.rs

@@ -981,6 +981,75 @@ impl BinOpKind {
 
 pub type BinOp = Spanned<BinOpKind>;
 
+// Sometimes `BinOpKind` and `AssignOpKind` need the same treatment. The
+// operations covered by `AssignOpKind` are a subset of those covered by
+// `BinOpKind`, so it makes sense to convert `AssignOpKind` to `BinOpKind`.
+impl From<AssignOpKind> for BinOpKind {
+    fn from(op: AssignOpKind) -> BinOpKind {
+        match op {
+            AssignOpKind::AddAssign => BinOpKind::Add,
+            AssignOpKind::SubAssign => BinOpKind::Sub,
+            AssignOpKind::MulAssign => BinOpKind::Mul,
+            AssignOpKind::DivAssign => BinOpKind::Div,
+            AssignOpKind::RemAssign => BinOpKind::Rem,
+            AssignOpKind::BitXorAssign => BinOpKind::BitXor,
+            AssignOpKind::BitAndAssign => BinOpKind::BitAnd,
+            AssignOpKind::BitOrAssign => BinOpKind::BitOr,
+            AssignOpKind::ShlAssign => BinOpKind::Shl,
+            AssignOpKind::ShrAssign => BinOpKind::Shr,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Encodable, Decodable, HashStable_Generic)]
+pub enum AssignOpKind {
+    /// The `+=` operator (addition)
+    AddAssign,
+    /// The `-=` operator (subtraction)
+    SubAssign,
+    /// The `*=` operator (multiplication)
+    MulAssign,
+    /// The `/=` operator (division)
+    DivAssign,
+    /// The `%=` operator (modulus)
+    RemAssign,
+    /// The `^=` operator (bitwise xor)
+    BitXorAssign,
+    /// The `&=` operator (bitwise and)
+    BitAndAssign,
+    /// The `|=` operator (bitwise or)
+    BitOrAssign,
+    /// The `<<=` operator (shift left)
+    ShlAssign,
+    /// The `>>=` operator (shift right)
+    ShrAssign,
+}
+
+impl AssignOpKind {
+    pub fn as_str(&self) -> &'static str {
+        use AssignOpKind::*;
+        match self {
+            AddAssign => "+=",
+            SubAssign => "-=",
+            MulAssign => "*=",
+            DivAssign => "/=",
+            RemAssign => "%=",
+            BitXorAssign => "^=",
+            BitAndAssign => "&=",
+            BitOrAssign => "|=",
+            ShlAssign => "<<=",
+            ShrAssign => ">>=",
+        }
+    }
+
+    /// AssignOps are always by value.
+    pub fn is_by_value(self) -> bool {
+        true
+    }
+}
+
+pub type AssignOp = Spanned<AssignOpKind>;
+
 /// Unary operator.
 ///
 /// Note that `&data` is not an operator, it's an `AddrOf` expression.
@@ -1593,7 +1662,7 @@ pub enum ExprKind {
     /// An assignment with an operator.
     ///
     /// E.g., `a += 1`.
-    AssignOp(BinOp, P<Expr>, P<Expr>),
+    AssignOp(AssignOp, P<Expr>, P<Expr>),
     /// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct field.
     Field(P<Expr>, Ident),
     /// An indexing operation (e.g., `foo[2]`).