Use 64 bit types for dataset size calculation in CAGRA graph optimizer (#380)

This PR fixes #375.

Authors:
  - Tamas Bela Feher (https://github.com/tfeher)

Approvers:
  - Corey J. Nolet (https://github.com/cjnolet)

URL: #380

Author: tfeher

cpp/src/neighbors/detail/cagra/graph_core.cuh

@@ -475,12 +475,12 @@ void sort_knn_graph(
 {
   RAFT_EXPECTS(dataset.extent(0) == knn_graph.extent(0),
                "dataset size is expected to have the same number of graph index size");
-  const uint32_t dataset_size = dataset.extent(0);
-  const uint32_t dataset_dim  = dataset.extent(1);
+  const uint64_t dataset_size = dataset.extent(0);
+  const uint64_t dataset_dim  = dataset.extent(1);
   const DataT* dataset_ptr    = dataset.data_handle();
 
   const IdxT graph_size             = dataset_size;
-  const uint32_t input_graph_degree = knn_graph.extent(1);
+  const uint64_t input_graph_degree = knn_graph.extent(1);
   IdxT* const input_graph_ptr       = knn_graph.data_handle();
 
   auto large_tmp_mr = raft::resource::get_large_workspace_resource(res);
@@ -528,7 +528,7 @@ void sort_knn_graph(
     kernel_sort                        = kern_sort<DataT, IdxT, numElementsPerThread>;
   } else {
     RAFT_FAIL(
-      "The degree of input knn graph is too large (%u). "
+      "The degree of input knn graph is too large (%lu). "
       "It must be equal to or smaller than %d.",
       input_graph_degree,
       1024);