In some cases we would hash or memcmp against structs with bools or
other non-filled data. This could have implementation differences,
and may have been causing cache errors on Clang.

BUG=chromium:721648
BUG=angleproject:2044

Change-Id: I981a1e6e8d50a33f7fade568497b72b919accfce
Reviewed-on: https://chromium-review.googlesource.com/516383Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>