Fix vector_dist_sparse with CUDA_BACKEND=SEQUENTIAL (static blockDim)

src/util/cudify/sequential/cudify_sequential.hpp

@@ -31,8 +31,8 @@ extern std::vector<void *>mem_stack;
 extern thread_local dim3 threadIdx;
 extern thread_local dim3 blockIdx;
 
-static dim3 blockDim;
-static dim3 gridDim;
+extern dim3 blockDim;
+extern dim3 gridDim;
 
 extern std::vector<void *> mem_stack;
 extern std::vector<boost::context::detail::fcontext_t> contexts;