message: Better patch for missing M_PI constants
diff: #include <openlibm_math.h>
  // Included to fix mesa issues
  -#define M_PI_2 (M_PI/2.0)
  -#define M_PI_4 (M_PI/4.0)
  +#ifndef M_PI
  +#define M_PI 3.14159265358979323846 /* pi */
  +#endif
  +
  +#ifndef M_PI_2
  +#define M_PI_2 1.57079632679489661923 /* pi/2 */
  +#endif
  +
  +#ifndef M_PI_4
  +#define M_PI_4 0.78539816339744830962 /* pi/4 */
  +#endif
  