* bootstrap (gnulib_modules): Add strverscmp.

* lib/.cvsignore: Add strverscmp.c, strverscmp.h.
* m4/.cvsignore: Add strverscmp.m4.
* src/parse-gram.y (%require): New token, new rule.
(version_check): New.
* src/scan-gram.l (%require): Adjust.
* tests/input.at (AT_REQUIRE): New.
Use it.
* doc/bison.texinfo (Require Decl): New.
(Calc++ Parser): Use %require.

lib/.cvsignore

@@ -54,6 +54,8 @@ strnlen.c
 strnlen.h
 strtol.c
 strtoul.c
+strverscmp.c
+strverscmp.h
 unistd--.h
 unistd-safer.h
 unlocked-io.h