Fix symlinks.
 [rsc] --rw-rw-r-- M 121854 glenda sys 2683 Oct 19 07:57 sys/src/cmd/tapefs/tarfs.c
	/n/sourcesdump/2005/1019/plan9/sys/src/cmd/tapefs/tarfs.c:61,71 - 
	/n/sourcesdump/2005/1020/plan9/sys/src/cmd/tapefs/tarfs.c:61,71
	  		||  strrchr(dblock.dbuf.name, '\0')[-1] == '/')
	  			f.mode |= DMDIR;
	  		f.mode &= DMDIR|0777;
	- 		linkflg = dblock.dbuf.linkflag=='s' || dblock.dbuf.linkflag=='1';
	+ 		linkflg = dblock.dbuf.linkflag=='5' || dblock.dbuf.linkflag=='1';
	  		isabs = dblock.dbuf.name[0]=='/';
	  		if (chksum != checksum()){
	  			fprint(1, "bad checksum on %.28s\n", dblock.dbuf.name);
	- 			abort();
	+ 			exits("checksum");
	  		}
	  		if (linkflg) {
	  			/*fprint(2, "link %s->%s skipped\n", dblock.dbuf.name,
	/n/sourcesdump/2005/1019/plan9/sys/src/cmd/tapefs/tarfs.c:99,105 - 
	/n/sourcesdump/2005/1020/plan9/sys/src/cmd/tapefs/tarfs.c:99,105
	  doread(Ram *r, long off, long cnt)
	  {
	  
	- 	seek(tapefile, (TBLOCK * (long)r->data)+off, 0);
	+ 	seek(tapefile, (TBLOCK * (vlong)r->data)+off, 0);
	  	if (cnt>sizeof(dblock.tbuf))
	  		error("read too big");
	  	read(tapefile, dblock.tbuf, cnt);
 [sys] --rwxrwxr-x M 121854 glenda sys 94353 Oct 19 23:08 386/bin/fs/tarfs
	/sys/src/cmd/tapefs/tarfs.c:doread
	/sys/src/cmd/tapefs/tarfs.c:populate