Revert of [turbofan] simplify gap ordering (patchset #2 id:20001 of https://codereview.chromium.org/810013002/)

Reason for revert:
Revert for breaking emscripten bullet with turbofan on android arm64.

Original issue's description:
> [turbofan] simplify gap ordering
>
> BUG=
>
> Committed: https://crrev.com/70b5eb47b39acbf31746f4a116a9b3ce2730218a
> Cr-Commit-Position: refs/heads/master@{#25865}

TBR=bmeurer@chromium.org,dcarney@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/815743002

Cr-Commit-Position: refs/heads/master@{#25888}