Merge branch 'po/size-t-for-vs'

On platforms where ulong is shorter than size_t, code paths that
shifted 1 or 1U to the left lacked the necessary cast to size_t,
which have been corrected.

* po/size-t-for-vs:
  object-file.c: LLP64 compatibility, upcast unity for left shift
  diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
  repack.c: LLP64 compatibility, upcast unity for left shift

diff --cc builtin/repack.c
Simple merge

diff --cc object-file.c
Simple merge