REGRESSION: MotionMark 1.1 regressed due to r260016
<rdar://problem/61898830>
Committed r260989: <https://trac.webkit.org/changeset/260989>
Reverted r260989 for reason: Mistakenly identified cause of MotionMark 1.1 performance regression Committed r261162: <https://trac.webkit.org/changeset/261162>