Use &'hir Expr everywhere.

For consistency, and because it makes HIR measurement simpler and more
accurate.

Author: nnethercote

clippy_lints/src/loops/never_loop.rs

@@ -178,9 +178,9 @@ fn never_loop_expr(expr: &Expr<'_>, main_loop_id: HirId) -> NeverLoopResult {
                 InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => {
                     never_loop_expr(expr, main_loop_id)
                 },
-                InlineAsmOperand::Out { expr, .. } => never_loop_expr_all(&mut expr.iter(), main_loop_id),
+                InlineAsmOperand::Out { expr, .. } => never_loop_expr_all(&mut expr.iter().copied(), main_loop_id),
                 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
-                    never_loop_expr_all(&mut once(in_expr).chain(out_expr.iter()), main_loop_id)
+                    never_loop_expr_all(&mut once(*in_expr).chain(out_expr.iter().copied()), main_loop_id)
                 },
                 InlineAsmOperand::Const { .. }
                 | InlineAsmOperand::SymFn { .. }

clippy_lints/src/utils/author.rs

@@ -595,7 +595,7 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
     }
 
     fn body(&self, body_id: &Binding<hir::BodyId>) {
-        let expr = &self.cx.tcx.hir().body(body_id.value).value;
+        let expr = self.cx.tcx.hir().body(body_id.value).value;
         bind!(self, expr);
         out!("let {expr} = &cx.tcx.hir().body({body_id}).value;");
         self.expr(expr);

clippy_utils/src/lib.rs

@@ -1804,7 +1804,7 @@ pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool
             }
         };
 
-        let mut expr = &func.value;
+        let mut expr = func.value;
         loop {
             match expr.kind {
                 #[rustfmt::skip]