This CL moves a number of memory-related methods out of utils into its
own header, since utils.h is included in many places that do not need
these methods.

R=clemensh@chromium.org,mstarzinger@chromium.org

Change-Id: I5155baf329844784286413408c05c7108b789020
Reviewed-on: https://chromium-review.googlesource.com/c/1354889
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57948}