Add test for setpgrp. Fixes #690317.
diff --git a/pyconfig.h.in b/pyconfig.h.in
index e0ab1b9..9d2447b 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -378,6 +378,9 @@
 /* Define to 1 if you have the `setpgid' function. */
 #undef HAVE_SETPGID
 
+/* Define to 1 if you have the `setpgrp' function. */
+#undef HAVE_SETPGRP
+
 /* Define to 1 if you have the `setregid' function. */
 #undef HAVE_SETREGID