Update.
* sysdeps/unix/sysv/linux/seteuid.c (seteuid): Use setresuid32
syscall directly if possible. If __ASSUME_SETRESUID_SYSCALL is
defined drop compatibility code.
* sysdeps/unix/sysv/linux/setegid.c (setegid): Use setresgid32
syscall directly if possible. If __ASSUME_SETRESUID_SYSCALL is
defined drop compatibility code.
* sysdeps/unix/sysv/linux/i386/seteuid.c (seteuid): Use
setresuid32 syscall directly if possible.
* sysdeps/unix/sysv/linux/i386/setegid.c (setegid): Use
setresgid32 syscall directly if possible.