Revert "Auto merge of #133734 - scottmcm:lower-indexing-to-ptrmetadata, r=davidtwco,RalfJung"

This reverts commit b57d93d8b9, reversing
changes made to 0aeaa5eb22.

compiler/rustc_middle/src/mir/consts.rs

@@ -467,9 +467,6 @@ impl<'tcx> Const<'tcx> {
                 let const_val = tcx.valtree_to_const_val((ty, valtree));
                 Self::Val(const_val, ty)
             }
-            ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args }) => {
-                Self::Unevaluated(UnevaluatedConst { def, args, promoted: None }, ty)
-            }
             _ => Self::Ty(ty, c),
         }
     }