Per request in https://codereview.chromium.org/1047213002/

These files will continue to have a lot of churn in next two months
as we finish support for MIPS r6 instruction set. When things settle
down, we will do a clang-format --full to clean them up. For now,
we'd prefer to be able to do easy diffs, and will do incremental
re-formats as we make changes.

BUG=

Review URL: https://codereview.chromium.org/1546973003

Cr-Commit-Position: refs/heads/master@{#33038}