The CL replaces several helper functions for memory load/store using
base register and offset with one helper function that contains several
optimizations.

BUG=

Change-Id: I187e7e882131552abd9a0b3a0070d78adefd25b6
Reviewed-on: https://chromium-review.googlesource.com/552119
Commit-Queue: Miran Karić <Miran.Karic@imgtec.com>
Reviewed-by: Ivica Bogosavljevic <ivica.bogosavljevic@imgtec.com>
Cr-Commit-Position: refs/heads/master@{#46420}