Rollup merge of rust-lang#123777 - oli-obk:operator_cleanup, r=jieyouxu

Deduplicate some function implementations between the parser and AST/HIR

These functions already existed on parser binops, so just convert back to them back and invoke the equivalent method.

Author: matthiaskrgr

compiler/rustc_ast/src/ast.rs

@@ -920,14 +920,8 @@ impl BinOpKind {
         matches!(self, BinOpKind::And | BinOpKind::Or)
     }
 
-    pub fn is_comparison(&self) -> bool {
-        use BinOpKind::*;
-        // Note for developers: please keep this match exhaustive;
-        // we want compilation to fail if another variant is added.
-        match *self {
-            Eq | Lt | Le | Ne | Gt | Ge => true,
-            And | Or | Add | Sub | Mul | Div | Rem | BitXor | BitAnd | BitOr | Shl | Shr => false,
-        }
+    pub fn is_comparison(self) -> bool {
+        crate::util::parser::AssocOp::from_ast_binop(self).is_comparison()
     }
 
     /// Returns `true` if the binary operator takes its arguments by value.

compiler/rustc_hir_pretty/src/lib.rs

@@ -1142,7 +1142,7 @@ impl<'a> State<'a> {
     }
 
     fn print_expr_binary(&mut self, op: hir::BinOp, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>) {
-        let assoc_op = bin_op_to_assoc_op(op.node);
+        let assoc_op = AssocOp::from_ast_binop(op.node);
         let prec = assoc_op.precedence() as i8;
         let fixity = assoc_op.fixity();
 
@@ -2328,33 +2328,6 @@ fn stmt_ends_with_semi(stmt: &hir::StmtKind<'_>) -> bool {
     }
 }
 
-fn bin_op_to_assoc_op(op: hir::BinOpKind) -> AssocOp {
-    use crate::hir::BinOpKind::*;
-    match op {
-        Add => AssocOp::Add,
-        Sub => AssocOp::Subtract,
-        Mul => AssocOp::Multiply,
-        Div => AssocOp::Divide,
-        Rem => AssocOp::Modulus,
-
-        And => AssocOp::LAnd,
-        Or => AssocOp::LOr,
-
-        BitXor => AssocOp::BitXor,
-        BitAnd => AssocOp::BitAnd,
-        BitOr => AssocOp::BitOr,
-        Shl => AssocOp::ShiftLeft,
-        Shr => AssocOp::ShiftRight,
-
-        Eq => AssocOp::Equal,
-        Lt => AssocOp::Less,
-        Le => AssocOp::LessEqual,
-        Ne => AssocOp::NotEqual,
-        Ge => AssocOp::GreaterEqual,
-        Gt => AssocOp::Greater,
-    }
-}
-
 /// Expressions that syntactically contain an "exterior" struct literal, i.e., not surrounded by any
 /// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
 /// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.