maint: remove -Wmissing-field-initializers workarounds

* configure.ac: Rather than disabling -Wmissing-field-initializers,
use the fact that gnulib now disables it automatically when required
(on versions of GCC older than 4.7).
* src/system.h: Remove the no longer needed DECLARE_ZEROED_AGGREGATE.
* src/ls.c: Likewise.
* src/pathchk.c: Likewise.
* src/shred.c: Likewise.
* src/stty.c: Likewise.
* src/wc.c: Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/wc.c b/src/wc.c
index 039921470..702a7a779 100644
--- a/src/wc.c
+++ b/src/wc.c
@@ -285,7 +285,7 @@ wc (int fd, char const *file_x, struct fstatus *fstatus)
     {
       bool in_word = false;
       uintmax_t linepos = 0;
-      DECLARE_ZEROED_AGGREGATE (mbstate_t, state);
+      mbstate_t state = { 0, };
       bool in_shift = false;
 # if SUPPORT_OLD_MBRTOWC
       /* Back-up the state before each multibyte character conversion and