bug#56551: 29.0.50; Errors in xterm.c when building --without-all

[Stefan Kangas <stefan@marxist.se>]

Eli Zaretskii <eliz@gnu.org> writes:

> Did I succeed to fix this now?

Thanks, it builds now.  These warnings remain, in case they're worth
fixing:

xterm.c: In function ‘x_scroll_bar_expose’:
xterm.c:14970:20: warning: variable ‘height’ set but not used
[-Wunused-but-set-variable]
14970 |   int x, y, width, height;
      |                    ^~~~~~
xterm.c:14970:13: warning: variable ‘width’ set but not used
[-Wunused-but-set-variable]
14970 |   int x, y, width, height;
      |             ^~~~~
xterm.c:14970:10: warning: variable ‘y’ set but not used
[-Wunused-but-set-variable]
14970 |   int x, y, width, height;
      |          ^
xterm.c:14970:7: warning: variable ‘x’ set but not used
[-Wunused-but-set-variable]
14970 |   int x, y, width, height;
      |       ^
xterm.c: In function ‘mark_xterm’:
xterm.c:27942:7: warning: unused variable ‘i’ [-Wunused-variable]
27942 |   int i;
      |       ^

In file included from gtkutil.c:29:
gtkutil.c: In function ‘xg_free_frame_widgets’:
gtkutil.c:1890:17: warning: implicit declaration of function
‘FRAME_X_DOUBLE_BUFFERED_P’ [-Wimplicit-function-declaration]
 1890 |       eassert (!FRAME_X_DOUBLE_BUFFERED_P (f));
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
lisp.h:174:43: note: in definition of macro ‘eassert’
  174 | # define eassert(cond) ((void) (false && (cond))) /* Check
COND compiles.  */
      |                                           ^~~~
gtkutil.c:1890:17: warning: nested extern declaration of
‘FRAME_X_DOUBLE_BUFFERED_P’ [-Wnested-externs]
 1890 |       eassert (!FRAME_X_DOUBLE_BUFFERED_P (f));
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~
lisp.h:174:43: note: in definition of macro ‘eassert’
  174 | # define eassert(cond) ((void) (false && (cond))) /* Check
COND compiles.  */
      |                                           ^~~~