New macro.
(PSEUDO): Use it instead of SYSCALL_PIC_SETUP and jmp syscall_error.
* sysdeps/unix/sysv/linux/i386/sysdep.S (__syscall_error): Define
only #ifndef PIC.
* Makeconfig (built-program-cmd): New variable.
* sunrpc/Makefile (rpcgen-cmd): Use $(built-program-cmd).
* time/Makefile (zic-cmd): Likewise.
* hurd/Makefile (user-interfaces): Add hurd/exec_startup.