Merge pull request #256 from apple/revert-255-revert-254-das-darwin-libdispatch-890-merge-master

Re-merge darwin/libdispatch-890 to master

Signed-off-by: Daniel A. Steffen <dsteffen@apple.com>
diff --git a/PATCHES b/PATCHES
index f991571..95dae37 100644
--- a/PATCHES
+++ b/PATCHES
@@ -335,3 +335,4 @@
 [0b6c22e] APPLIED rdar://33531111
 [5a3c02a] APPLIED rdar://33531111
 [22df1e7] APPLIED rdar://33531111
+[21273de] APPLIED rdar://33531111