Fix problem finding libbfd support on some systems

ChangeLog

@@ -1,3 +1,10 @@
+2021-11-23 Richard Frith-Macdonald <rfm@gnu.org>
+
+	* configure.ac: check for zlib before bfd
+	* configure: regenerate
+	libbfd may need libz, so we must check for one before checking for
+	the other.
+
 2021-11-21 Gregory John Casamento <greg.casamento@gmail.com>
 
 	* Headers/Foundation/NSURLConnection.h: Add

configure

@@ -9362,6 +9362,51 @@ _ACEOF
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gzseek in -lz" >&5
+$as_echo_n "checking for gzseek in -lz... " >&6; }
+if ${ac_cv_lib_z_gzseek+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lz  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char gzseek ();
+int
+main ()
+{
+return gzseek ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_z_gzseek=yes
+else
+  ac_cv_lib_z_gzseek=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_z_gzseek" >&5
+$as_echo "$ac_cv_lib_z_gzseek" >&6; }
+if test "x$ac_cv_lib_z_gzseek" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBZ 1
+_ACEOF
+
+  LIBS="-lz $LIBS"
+
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for bfd_openr in -lbfd" >&5
 $as_echo_n "checking for bfd_openr in -lbfd... " >&6; }
 if ${ac_cv_lib_bfd_bfd_openr+:} false; then :

configure.ac

@@ -2420,6 +2420,7 @@ fi
 AC_CHECK_HEADERS(bfd.h)
 AC_CHECK_LIB(intl, libintl_fprintf)
 AC_CHECK_LIB(iberty, dyn_string_append)
+AC_CHECK_LIB(z, gzseek)
 AC_CHECK_LIB(bfd, bfd_openr)
 
 AC_TRY_COMPILE([