[PATCH] shell: fix $(()) precedence bug in "X=A?B:C" (it is _not_ "(X=A)?..)"

[Steffen Nurpmeso]

Denys Vlasenko wrote in
 <CAK1hOcOU1R8PaxN26b5Pc_Ob-XoSrwNsEz1y888pujmfmDZgjw at mail.gmail.com>:
 |Your patches seem to be against dash, not busybox git tree?

No?  I think dash uses a yacc thing..?  (That only supports the
most basic things, as per POSIX, which is two steps back for
busybox.  But smaller i presume.)

And sorry for lots of noise over weeks!  I have

  * 863f859305 (HEAD -> refs/heads/sharith-v3) shell: $(()): add tests
  * 5a27561d08 shell: $(()): sync (comments, a bit reorder, one small fix)
  * 038a85a843 shell: plug SH_MATH_ERROR_TRACK memory leak
  * 294a4dca78 shell: exchange Dijkstra $(( )) evaluator..
  * 526625bc83 (refs/remotes/origin/master, refs/remotes/origin/HEAD, refs/heads/master) libbb: mark stack in assembly files read-only

'Rebased just fine.  But you can have a big all-in-one v4 if you
want?  (I do not expect anything more to happen anytime soon.)

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)