TensorReferenceGroup::promotedFootprint: preserve tensor id

It is not clear why the tensor id got removed before,
but it needs to be preserved to be able to check compatibility
with the sizes in the next commit.

Author: Sven Verdoolaege

tc/core/polyhedral/memory_promotion.cc

@@ -108,8 +108,7 @@ bool TensorReferenceGroup::isReadOnly() const {
 }
 
 isl::set TensorReferenceGroup::promotedFootprint() const {
-  auto space =
-      scopedAccesses().get_space().range().reset_tuple_id(isl::dim_type::set);
+  auto space = scopedAccesses().get_space().range();
   auto sizes = approximationSizes();
   if (sizes.size() != space.dim(isl::dim_type::set)) {
     throw promotion::GroupingError("unexpected dimensionality mismatch");