cmake HAVE_X86_64_POPCNTQ examples

MobilityDB/MobilityDB CMakeLists.txt :243

check_c_source_runs("
#include <stdint.h>
int main() {
    uint64_t x = 1, r;
    __asm__ (\"popcntq %1, %0\" : \"=r\"(r) : \"r\"(x));
    return 0;
}" HAVE_X86_64_POPCNTQ)