Include <math.h> header before trying to #define M_PI and M_SQRT2. (Needed for AIX tinderbox build.)

other-licenses/libart_lgpl/art_misc.h

@@ -24,6 +24,7 @@
 #define __ART_MISC_H__
 
 #include <stdlib.h> /* for malloc, etc.  */
+#include <math.h>   /* for M_PI, M_SQRT2 */
 
 /* The art_config.h file is automatically generated by
    gen_art_config.c and contains definitions of