Implement the ExecV system call.
<br>
ExecV is like Exec, except that it allows an array
of parameters to be passed to the newly created process.
From syscall.h:

<pre>
/* Run the executable, stored in the Nachos file "argv[0]", with
 * parameters stored in argv[1..argc-1] and return a
 * unique non-negative process identifier for the new process.
 * Returns a negative value in case of failure.
 *
 * A few example error codes might be:
 *    NACHOS_ENAMETOOLONG path to executable uses too many characters
 *    NACHOS_EREACHEDLIMIT too many arguments to handle properly
 *    NACHOS_EINVAL one or more arguments is not valid
 */
ProcessId ExecV(int argc, char* argv[]);
</pre>

<br>
The application running in the new process should be able to
access these parameters through the argc and argv
parameters to the application's main function.

For example the following C program (PrintArgs) will print
out all of its command line arguments.
<pre>
#include "syscall.h"

int
main(int argc, char *argv[])
{
  int i;

  for (i=0; i&#60argc; i++) {
    print("Arg ");
    printInt(i);
    print(" = ");
    print(argv[i]);
    print("\n");
  }

  Exit(0);
}
</pre>

So for example if another program
starts the program above as follows:

<pre>
char *pgm = "PrintArgs";
char *arg1 = "1";
char *arg2 = "2";
char *arg2 = "arg3";
char *arg3 = "thatsall";
char *arglist[5];
arglist[0] = pgm;
arglist[1] = arg1;
arglist[2] = arg2;
arglist[3] = arg2;
arglist[4] = arg3;

ExecV(5, arglist);
</pre>

Would result in the following output:

<pre>
Arg 0 = PrintArgs
Arg 1 = 1
Arg 2 = 2
Arg 3 = arg3
Arg 4 = thatsall
</pre>