Revert of [turbofan][arm64] Match fneg for -0.0 - x pattern. (patchset #1 id:1 of...

Revert of [turbofan][arm64] Match fneg for -0.0 - x pattern. (patchset #1 id:1 of https://codereview.chromium.org/1013743006/)

Reason for revert:
Revert due to crash.

Original issue's description:
> [turbofan][arm64] Match fneg for -0.0 - x pattern.
>
> Note that this patch add an extra bit to the ArchOpcodeField.
>
> R=bmeurer@chromium.org
>
> Committed: https://crrev.com/fe7441225100660d01e66ce3bcaefe368f62df81
> Cr-Commit-Position: refs/heads/master@{#27494}

TBR=bmeurer@chromium.org,baptiste.afsa@arm.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1041633002

Cr-Commit-Position: refs/heads/master@{#27495}