message: Make M_PI available on MSVC.
diff: @@ -14,6 +14,8 @@ limitations under the License.
  ==============================================================================*/
  #include "tensorflow/lite/experimental/microfrontend/lib/window_util.h"
  +// This macro is required to make MSVC defines math constants in math.h
  +#define _USE_MATH_DEFINES
  #include <math.h>
  #include <stdio.h>
  #include <stdlib.h>
  