64-bit fixes.
 [jmk] --rw-rw-r-- M 107020 glenda sys 10050 Nov 19 20:57 sys/src/cmd/hoc/code.c
	/n/sourcesdump/2005/1119/plan9/sys/src/cmd/hoc/code.c:165,171 - 
	/n/sourcesdump/2005/1120/plan9/sys/src/cmd/hoc/code.c:165,171
	  		execerror(sp->name, "call nested too deeply");
	  	fp++;
	  	fp->sp = sp;
	- 	fp->nargs = (int)pc[1];
	+ 	fp->nargs = (int)(uintptr)pc[1];
	  	fp->retpc = pc + 2;
	  	fp->argn = stackp - 1;	/* last argument */
	  	if(fp->nargs != sp->u.defn->nargs)