$core_dumped = ($? >> 15) & 1;

00000000 00000000 CSSSSSSS EEEEEEEE

   >> 15

00000000 00000000 00000000 0000000C

   & 1

00000000 00000000 00000000 00000001 = 1
00000000 00000000 00000000 0000000C