message: Define SIGKILL when running grpc_client_test on windows.
diff: @@ -34,6 +34,12 @@ limitations under the License.
  #include "tensorflow/core/platform/subprocess.h"
  #include "tensorflow/core/platform/test.h"
  +#if defined(PLATFORM_WINDOWS)
  +// This is not used on windows, but we define it here to make the test simpler
  +// to write below.
  +#define SIGKILL -1
  +#endif
  +
  namespace xla {
  namespace {
  