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, 3 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 55a16b237e5..534b9e40da3 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3552,8 +3552,8 @@ void
 fix_start_end_in_overlays (register ptrdiff_t start, register ptrdiff_t end)
 {
   Lisp_Object overlay;
-  struct Lisp_Overlay *before_list IF_LINT (= NULL);
-  struct Lisp_Overlay *after_list IF_LINT (= NULL);
+  struct Lisp_Overlay *before_list;
+  struct Lisp_Overlay *after_list;
   /* These are either nil, indicating that before_list or after_list
      should be assigned, or the cons cell the cdr of which should be
      assigned.  */
@@ -3700,7 +3700,7 @@ fix_overlays_before (struct buffer *bp, ptrdiff_t prev, ptrdiff_t pos)
   /* If parent is nil, replace overlays_before; otherwise, parent->next.  */
   struct Lisp_Overlay *tail = bp->overlays_before, *parent = NULL, *right_pair;
   Lisp_Object tem;
-  ptrdiff_t end IF_LINT (= 0);
+  ptrdiff_t end;
 
   /* After the insertion, the several overlays may be in incorrect
      order.  The possibility is that, in the list `overlays_before',