Rollup merge of #108958 - clubby789:unbox-the-hir, r=compiler-errors

Remove box expressions from HIR

After #108516, `#[rustc_box]` is used at HIR->THIR lowering and this is no longer emitted, so it can be removed.

This is based on top of #108471 to help with conflicts, so 43490488ccacd1a822e9c621f5ed6fca99959a0b is the only relevant commit (sorry for all the duplicated pings!)

````@rustbot```` label +S-blocked

5 files changed, 2 insertions, 7 deletions

diff --git a/src/tools/clippy/clippy_utils/src/check_proc_macro.rs b/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
index 43f0df145f0..d3a6929f67e 100644
--- a/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
+++ b/src/tools/clippy/clippy_utils/src/check_proc_macro.rs
@@ -112,7 +112,6 @@ fn qpath_search_pat(path: &QPath<'_>) -> (Pat, Pat) {
 /// Get the search patterns to use for the given expression
 fn expr_search_pat(tcx: TyCtxt<'_>, e: &Expr<'_>) -> (Pat, Pat) {
     match e.kind {
-        ExprKind::Box(e) => (Pat::Str("box"), expr_search_pat(tcx, e).1),
         ExprKind::ConstBlock(_) => (Pat::Str("const"), Pat::Str("}")),
         ExprKind::Tup([]) => (Pat::Str(")"), Pat::Str("(")),
         ExprKind::Unary(UnOp::Deref, e) => (Pat::Str("*"), expr_search_pat(tcx, e).1),
diff --git a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
index ee2f816f181..babbc7294a1 100644
--- a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
+++ b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
@@ -199,8 +199,7 @@ fn expr_eagerness<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> EagernessS
                 },
 
                 // Memory allocation, custom operator, loop, or call to an unknown function
-                ExprKind::Box(_)
-                | ExprKind::Unary(..)
+                ExprKind::Unary(..)
                 | ExprKind::Binary(..)
                 | ExprKind::Loop(..)
                 | ExprKind::Call(..) => self.eagerness = Lazy,
diff --git a/src/tools/clippy/clippy_utils/src/hir_utils.rs b/src/tools/clippy/clippy_utils/src/hir_utils.rs
index 0603755f8a9..3a6d23ca5c1 100644
--- a/src/tools/clippy/clippy_utils/src/hir_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/hir_utils.rs
@@ -249,7 +249,6 @@ impl HirEqInterExpr<'_, '_, '_> {
                 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
                     && both(le, re, |l, r| self.eq_expr(l, r))
             },
-            (&ExprKind::Box(l), &ExprKind::Box(r)) => self.eq_expr(l, r),
             (&ExprKind::Call(l_fun, l_args), &ExprKind::Call(r_fun, r_args)) => {
                 self.inner.allow_side_effects && self.eq_expr(l_fun, r_fun) && self.eq_exprs(l_args, r_args)
             },
@@ -628,7 +627,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                     self.hash_expr(j);
                 }
             },
-            ExprKind::Box(e) | ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
+            ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
                 self.hash_expr(e);
             },
             ExprKind::Call(fun, args) => {
diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs
index 85bf28b708b..44cb5d5756a 100644
--- a/src/tools/clippy/clippy_utils/src/sugg.rs
+++ b/src/tools/clippy/clippy_utils/src/sugg.rs
@@ -133,7 +133,6 @@ impl<'a> Sugg<'a> {
 
         match expr.kind {
             hir::ExprKind::AddrOf(..)
-            | hir::ExprKind::Box(..)
             | hir::ExprKind::If(..)
             | hir::ExprKind::Let(..)
             | hir::ExprKind::Closure { .. }
diff --git a/src/tools/clippy/clippy_utils/src/visitors.rs b/src/tools/clippy/clippy_utils/src/visitors.rs
index d27a20bd4df..86a93f64fb7 100644
--- a/src/tools/clippy/clippy_utils/src/visitors.rs
+++ b/src/tools/clippy/clippy_utils/src/visitors.rs
@@ -600,7 +600,6 @@ pub fn for_each_unconsumed_temporary<'tcx, B>(
                 helper(typeck, false, e, f)?;
             },
             ExprKind::Block(&Block { expr: Some(e), .. }, _)
-            | ExprKind::Box(e)
             | ExprKind::Cast(e, _)
             | ExprKind::Unary(_, e) => {
                 helper(typeck, true, e, f)?;