Darwin/Mac: Also exclude OS X generated source
diff --git a/.gitignore b/.gitignore
index 6af76ac..06c18a2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,3 +19,4 @@ autom4te.cache
libffi.xcodeproj/xcuserdata
libffi.xcodeproj/project.xcworkspace
ios/
+osx/