pollution: setpgrp
pid_t setpgrp(void) __asm("_" "setpgrp" ); 

pollution: ualarm
useconds_t ualarm(useconds_t, useconds_t); 

pollution: usleep
int usleep(useconds_t) __asm("_" "usleep" ); 

pollution: vfork
pid_t vfork(void) __attribute__((availability(watchos,unavailable))) __attribute__((availability(tvos,unavailable)));