[Zucchini] Add helpers for 2 byte and 4 byte alignment.

This CL adds specialized versions of AlignCeil():
  {IncrementForAlignCeil2(), IncrementForAlignCeil4()}.

Given a value to be aligned, these functions return an increment that
the caller can add to the given value to cause alignment. This scheme
admits iterator alignment. e.g., by:
  aligned_it = it + IncrementForAlignCeil4(it - base_it);

These functions will be used by code to add ARM support.

Bug: 918867
Change-Id: I6da038a748a29cde82e4c82e597455644213abd9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1524920
Reviewed-by: Samuel Huang <huangs@chromium.org>
Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Commit-Queue: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641279}
NOKEYCHECK=True
GitOrigin-RevId: dc2c91d1d1cf5aeac19b25210e470909f175b160

0 files changed, 0 insertions, 0 deletions