test/Sema/return.c: Cygwin does not have _longjmp().

Although Cygwin-1.7 has _longjmp(), it would not be essential for this
to distinguish Cygwin's version with <cygwin/version.h>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116783 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/return.c b/test/Sema/return.c
index 597b502..0c2c72e 100644
--- a/test/Sema/return.c
+++ b/test/Sema/return.c
@@ -203,7 +203,7 @@
   if (j)
     longjmp(test30_j, 1);
   else
-#if defined(_WIN32) || defined(_WIN64)
+#if defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
     longjmp(test30_j, 2);
 #else
     _longjmp(test30_j, 1);