Revert of [arm] Fix recognition of VNEG. (patchset #3 id:40001 of https://codereview.chromium.org/762493006/)

Reason for revert:
Breaks arm compilation.

Original issue's description:
> [arm] Fix recognition of VNEG.
>
> TEST=mjsunit,unittests
> R=svenpanne@chromium.org
>
> Committed: https://chromium.googlesource.com/v8/v8/+/2aed882fe74dbf9210159babe30fedccd900e7cf

TBR=svenpanne@chromium.org,bmeurer@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/751653004

Cr-Commit-Position: refs/heads/master@{#25514}