Auto merge of #116707 - cjgillot:slice-id, r=oli-obk,RalfJung

Create an `AllocId` for `ConstValue::Slice`.

This PR modifies `ConstValue::Slice` to use an `AllocId` instead of directly manipulating the allocation. This was originally proposed by rust-lang/rust#115764 but was a perf regression.

Almost 2 years later, enough code has changed to make this a perf improvement: rust-lang/rust#116707 (comment)

Author: bors

clippy_lints/src/non_copy_const.rs

@@ -338,7 +338,7 @@ impl<'tcx> NonCopyConst<'tcx> {
         tcx: TyCtxt<'tcx>,
         typing_env: TypingEnv<'tcx>,
         ty: Ty<'tcx>,
-        val: ConstValue<'tcx>,
+        val: ConstValue,
     ) -> Result<bool, ()> {
         let ty = tcx.try_normalize_erasing_regions(typing_env, ty).unwrap_or(ty);
         match self.is_ty_freeze(tcx, typing_env, ty) {
@@ -477,7 +477,7 @@ impl<'tcx> NonCopyConst<'tcx> {
         typing_env: TypingEnv<'tcx>,
         typeck: &'tcx TypeckResults<'tcx>,
         mut src_expr: &'tcx Expr<'tcx>,
-        mut val: ConstValue<'tcx>,
+        mut val: ConstValue,
     ) -> Result<Option<BorrowSource<'tcx>>, ()> {
         let mut parents = tcx.hir_parent_iter(src_expr.hir_id);
         let mut ty = typeck.expr_ty(src_expr);