Port 9af9f1d0

Original commit message:
These operators compute the absolute floating point value of some
arbitrary input, and are implemented without any branches (i.e. using
vabs on arm, and andps/andpd on x86).

R=mbrandy@us.ibm.com

BUG=

Review URL: https://codereview.chromium.org/1072963002

Cr-Commit-Position: refs/heads/master@{#27727}