t / t4101 / diff.3-0on commit builtin-gc.c: use new pack_keep bitfield to detect .keep file existence (01af249)
   1--- a/frotz
   2+++ b/frotz
   3@@ -1,3 +1,2 @@
   4 a
   5-c
   6-b
   7\ No newline at end of file
   8+b