Merge branch 'nd/pack-deltify-regression-fix'

In a recent update in 2.18 era, "git pack-objects" started
producing a larger than necessary packfiles by missing
opportunities to use large deltas.

* nd/pack-deltify-regression-fix:
pack-objects: fix performance issues on packing large deltas

diff --cc builtin/pack-objects.c
Simple merge

diff --cc pack-objects.c
Simple merge

diff --cc pack-objects.h
index 08c6b57d49791556f323ebf8654e98689a19593c,6ffbdcf79f3f52bd7a479e1fa6e1f02c9e54e205..62806ccc39ea31b425089f4f38121d81a02fe5dd
--- 1/pack-objects.h
--- 2/pack-objects.h
+++ b/pack-objects.h
@@@ -2,9 -2,7 +2,10 @@@
  #define PACK_OBJECTS_H
  
  #include "object-store.h"
+ #include "thread-utils.h"
 +#include "pack.h"
 +
 +#define DEFAULT_DELTA_CACHE_SIZE (256 * 1024 * 1024)
  
  #define OE_DFS_STATE_BITS     2
  #define OE_DEPTH_BITS         12