bugfix: make sure we don't exceed scratch size capacity in BF::query

src/spatial/detail/ArborX_BruteForceImpl.hpp

@@ -63,6 +63,18 @@ struct BruteForceImpl
     int const n_indexables = values.size();
     int const n_predicates = predicates.size();
     int max_scratch_size = TeamPolicy::scratch_size_max(0);
+    // FIXME: adjust max_scratch_size to compensate for potential alignment
+    // additions to make sure we don't accidentally exceed capacity
+    // 8 is a magical valie of scratch_memory_space::ALIGN in Kokkos
+    int indexable_alignment =
+        std::max({sizeof(IndexableType), alignof(IndexableType),
+                  static_cast<size_t>(8)});
+    int predicate_alignment =
+        std::max({sizeof(PredicateType), alignof(PredicateType),
+                  static_cast<size_t>(8)});
+    max_scratch_size = Kokkos::max(0, max_scratch_size - indexable_alignment -
+                                          predicate_alignment);
+
     // half of the scratch memory used by predicates and half for indexables
     int const predicates_per_team =
         max_scratch_size / 2 / sizeof(PredicateType);
@@ -87,6 +99,7 @@ struct BruteForceImpl
                      Kokkos::MemoryTraits<Kokkos::Unmanaged>>;
     int scratch_size = ScratchPredicateType::shmem_size(predicates_per_team) +
                        ScratchIndexableType::shmem_size(indexables_per_team);
+    ARBORX_ASSERT(scratch_size <= max_scratch_size);
 
     Kokkos::parallel_for(
         "ArborX::BruteForce::query::spatial::"