* interp.c (sim_create_inferior): Record program arguments for

* interp.c (sim_create_inferior): Record program arguments for
later inspection by the trap handler.
(count_argc): New function.
(prog_argv): Declare static.
(sim_write): Declare.
(trap): Implement argc, argnlen and argn system calls. Do not
abort on unknown system calls--simply return -1.
* syscall.h (SYS_argc, SYS_argnlen, SYS_argn): Define.