We've recently run into several platform- and compiler-specific errors
and warnings about alignment. This tentatively implements
AlignToDataAlignment for all platforms, which is used when setting up
the

 v8_Default_embedded_blob_
 v8_Default_embedded_blob_size_

variables.

Bug: v8:6666,chromium:929205
Change-Id: I0cee09eda71551f8b7d14f4076da496057023146
Reviewed-on: https://chromium-review.googlesource.com/c/1458018
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59428}