MachineOperatorBuilder was instantiated with default parameters
and this caused unaligned memory access errors.

Bug: 
Change-Id: Id95d074b2641ba4f002171b5c2990a520879f490
Reviewed-on: https://chromium-review.googlesource.com/720812Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#48588}