Omit IF_LINT code that no longer seems needed

Nowadays GCC is smarter, or the Emacs code has mutated, or both,
and now is as good a time as any to remove uses of IF_LINT that
now seem to be unnecessary.
* lib-src/emacsclient.c (set_local_socket):
* lib-src/movemail.c (main) [MAIL_USE_MAILLOCK && HAVE_TOUCHLOCK]:
* src/buffer.c (fix_start_end_in_overlays, fix_overlays_before):
* src/casefiddle.c (casify_region):
* src/charset.c (load_charset_map):
* src/coding.c (decode_coding_object, encode_coding_object):
* src/data.c (Fmake_variable_buffer_local, Fmake_local_variable)
(cons_to_unsigned, cons_to_signed):
* src/frame.c (make_frame, x_set_frame_parameters):
* src/keyboard.c (read_event_from_main_queue):
* src/regex.c (regex_compile):
* src/syntax.c (back_comment):
* src/window.c (Frecenter):
* src/xfaces.c (Fx_list_fonts):
Remove IF_LINT that no longer seems necessary.
* src/image.c (png_load_body, jpeg_load_body): Simplify use of IF_LINT.
* src/keyboard.c (read_char): Use IF_LINT (volatile) rather than
a pragma dance to pacify GCC -Wclobbered.
* src/xdisp.c (x_produce_glyphs): Rewrite to avoid need for IF_LINT.

* src/xterm.c (x_connection_closed): Now _Noreturn, which should
mean we do not need IF_LINT any more.
(x_io_error_quitter): Now _Noreturn.  Put an 'assume (false)’
at the end, to forestall warnings from older compilers.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/xterm.c b/src/xterm.c
index beef61d1618..9fb19a16f60 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -9393,7 +9393,7 @@ static char *error_msg;
 /* Handle the loss of connection to display DPY.  ERROR_MESSAGE is
    the text of an error message that lead to the connection loss.  */
 
-static void
+static _Noreturn void
 x_connection_closed (Display *dpy, const char *error_message, bool ioerror)
 {
   struct x_display_info *dpyinfo = x_display_info_for_display (dpy);
@@ -9491,9 +9491,6 @@ For details, see etc/PROBLEMS.\n",
   unbind_to (idx, Qnil);
   clear_waiting_for_input ();
 
-  /* Tell GCC not to suggest attribute 'noreturn' for this function.  */
-  IF_LINT (if (! terminal_list) return; )
-
   /* Here, we absolutely have to use a non-local exit (e.g. signal, throw,
      longjmp), because returning from this function would get us back into
      Xlib's code which will directly call `exit'.  */
@@ -9559,7 +9556,7 @@ x_error_quitter (Display *display, XErrorEvent *event)
    It kills all frames on the display that we lost touch with.
    If that was the only one, it prints an error message and kills Emacs.  */
 
-static int
+static _Noreturn int
 x_io_error_quitter (Display *display)
 {
   char buf[256];
@@ -9567,7 +9564,7 @@ x_io_error_quitter (Display *display)
   snprintf (buf, sizeof buf, "Connection lost to X server '%s'",
             DisplayString (display));
   x_connection_closed (display, buf, true);
-  return 0;
+  assume (false);
 }
 
 /* Changing the font of the frame.  */