BUG=chromium:476592
LOG=n

Review URL: https://codereview.chromium.org/1086333002

Cr-Commit-Position: refs/heads/master@{#27898}

This reverts commit 8c98cc07
because it causes flaky failures in the dromaeo.jslibeventprototype
benchmark on Linux/Windows and consistent failures on Android.

Also reverts the followup "Remove kForInStatementIsNotFastCase bailout reason"
(commit ba24e676) to avoid breaking the build.

BUG=chromium:476592
TBR=verwaest@chromium.org
LOG=y

Review URL: https://codereview.chromium.org/1066663005

Cr-Commit-Position: refs/heads/master@{#27859}

BUG=

Review URL: https://codereview.chromium.org/1075933003

Cr-Commit-Position: refs/heads/master@{#27748}