[mlir][sparse][gpu] Add explaining string to three static_assert stmts

mlir/lib/ExecutionEngine/CudaRuntimeWrappers.cpp

struct cusparseLtSpMatHandleAndData {
   void *values{nullptr};
 };
 
 struct cusparseLtDnMatHandleAndData {
   cusparseLtMatDescriptor_t mat;
   void *values{nullptr};
 };
 
-static_assert(sizeof(cusparseLtHandle_t) == 11024);
-static_assert(sizeof(cusparseLtSpMatHandleAndData) == 44104);
-static_assert(sizeof(cusparseLtDnMatHandleAndData) == 11032);
+static_assert(sizeof(cusparseLtHandle_t) == 11024,
+              "Unexpected cusparseLt handle size");
+static_assert(sizeof(cusparseLtSpMatHandleAndData) == 44104,
+              "Unexpected cusparseLt sparse matrix handle size");
+static_assert(sizeof(cusparseLtDnMatHandleAndData) == 11032,
+              "Unexpected cusparseLt dense matrix handle size");
 
 extern "C" MLIR_CUDA_WRAPPERS_EXPORT void
 mgpuCreateSparseLtEnv(void *h, CUstream /*stream*/) {
   // note that cuSparseLt still uses cusparseStatus_t
   CUSPARSE_REPORT_IF_ERROR(
       cusparseLtInit(reinterpret_cast<cusparseLtHandle_t *>(h)))
 }