bug#25128: Reorder lisp.h to declare types before using them

[Eli Zaretskii]

> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sun, 25 Dec 2016 09:38:14 -0800
> 
> I installed this patch, after fixing it up to work with the concurrency 
> branch.

Thanks.

However, it breaks the MS-Windows 32-bit build --with-wide-int:

  In file included from scroll.c:25:0:
  lisp.h:1001:1: error: redefinition of 'XUNTAG'
   XUNTAG (Lisp_Object a, int type)
   ^
  In file included from scroll.c:25:0:
  lisp.h:630:2: note: previous definition of 'XUNTAG' was here
   (XUNTAG) (Lisp_Object a, int type)
    ^

and similarly in all the other files in src.

In case this matters, the compiler switches are

  CFLAGS = -O0 -gdwarf-4 -g3

Let me know if I can help by providing further information.

(A 64-bit GNU/Linux build succeeds, not surprisingly.)