Fix native windows build by adding signal.h back into the include list.

  * gcc/ada/adaint.c: Added signal.h for Windows.

From-SVN: r241907

gcc/ada/ChangeLog

+2016-11-07  Tamar Christina  <tamar.christina@arm.com>
+
+	* adaint.c: Added signal.h for Windows.
+
 2016-10-31  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc-interface/misc.c (gnat_get_array_descr_info): Clear rank field.

gcc/ada/adaint.c

@@ -190,6 +190,7 @@ UINT CurrentCCSEncoding;
 #include <accctrl.h>
 #include <aclapi.h>
 #include <tlhelp32.h>
+#include <signal.h>
 #undef DIR_SEPARATOR
 #define DIR_SEPARATOR '\\'