Issue #4279: Fix build of parsermodule under Cygwin.
diff --git a/Python/graminit.c b/Python/graminit.c
index e65a992..ec2f421 100644
--- a/Python/graminit.c
+++ b/Python/graminit.c
@@ -2,6 +2,7 @@
 
 #include "pgenheaders.h"
 #include "grammar.h"
+PyAPI_DATA(grammar) _PyParser_Grammar;
 static arc arcs_0_0[3] = {
 	{2, 1},
 	{3, 1},