tests: fix regressions.

Exit status 63 is documented for version-mismatch.
	* bootstrap.conf (gnulib_modules): Remove sysexits.
	* src/system.h (EX_MISMATCH): Define.
	* src/parse-gram.y (version_check): Use it instead of EX_CONFIG.

Missing includes.
	* tests/calc.at, tests/named-refs.at: Include assert.h.
(cherry picked from commit 459a57a90f)

bootstrap.conf

@@ -25,7 +25,6 @@ gnulib_modules='
   mbswidth obstack perror pipe-posix progname
   quote quotearg realloc-posix
   spawn-pipe stdbool stpcpy strdup-posix strerror strtoul strverscmp
-  sysexits
   unistd unistd-safer unlocked-io update-copyright unsetenv verify
   warnings xalloc xalloc-die xstrndup
 

etc/bench.pl.in

@@ -134,8 +134,8 @@ sub calc_grammar ($$$)
     or die;
   print $out <<EOF;
 %{
+#include <assert.h>
 #include <stdio.h>
-
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>

src/parse-gram.y

@@ -759,7 +759,7 @@ version_check (location const *loc, char const *version)
     {
       complain_at (*loc, "require bison %s, but have %s",
                    version, PACKAGE_VERSION);
-      exit (EX_CONFIG);
+      exit (EX_MISMATCH);
     }
 }
 

src/system.h

@@ -52,7 +52,8 @@
 typedef size_t uintptr_t;
 #endif
 
-#include <sysexits.h>
+// Version mismatch.
+#define EX_MISMATCH 63
 
 /*---------.
 | Gnulib.  |

tests/calc.at

@@ -207,6 +207,7 @@ extern FILE *input;]AT_SKEL_CC_IF([[
 
 %code
 {
+#include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 #if HAVE_UNISTD_H

tests/named-refs.at

@@ -23,6 +23,7 @@ AT_SETUP([Tutorial calculator])
 AT_DATA_GRAMMAR([test.y],
 [[
 %{
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>