ash: undo "tokname hack"

ash: undo "tokname hack"

dash has tokendlist[] array to decide which tokens end lists.
We store it as first byte of each tokname_array[i].

Switch to bit array, name it like dash (tokendlist), drop special
1st byte of tokname_array[i]. This brings us closer to dash, and
shrinks the binary, because many more string aliasing opportunities
are now open:

function                                             old     new   delta
pstrcmp1                                               -      16     +16
readtoken1                                          2852    2858      +6
list                                                 326     327      +1
pstrcmp                                               16      15      -1
tokname                                               45      42      -3
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/2 up/down: 23/-4)              Total: 19 bytes
   text	   data	    bss	    dec	    hex	filename
 943556	    916	  14292	 958764	  ea12c	busybox_old
 943463	    916	  14292	 958671	  ea0cf	busybox_unstripped
^^^^^^^ note this!

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>