Reland r24737 "Read object pointer atomically while updating slots"

Crashes were fixed by r24914.

BUG=chromium:427746
LOG=N

Review URL: https://codereview.chromium.org/726543003

Cr-Commit-Position: refs/heads/master@{#25330}
Revert of Whitespace change to test the CQ. (patchset #1 id:1 of https://codereview.chromium.org/721113003/)

Reason for revert:
Test CQ

Original issue's description:
> Whitespace change to test the CQ.
>
> TBR=machenbach@chromium.org
> NOTRY=true
>
> Committed: https://chromium.googlesource.com/v8/v8/+/b0ab17592c8729535ebfa1f52131ee7f2b96b1e3

TBR=tandrii@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/725613002

Cr-Commit-Position: refs/heads/master@{#25331}
Revert "TransitionArray now uses <is_data_property, name, attributes> tuple as a key, which allows to have several entries for the same property name."
Revert "Fix for an assertion failure in Map::FindTransitionToField(...). Appeared after r25136."

This revert is made in order to revert r25099 which potentially causes renderer hangs.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/722873004

Cr-Commit-Position: refs/heads/master@{#25332}
PropertyAccessCompiler should always emit reloc info for external references.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/727483002

Cr-Commit-Position: refs/heads/master@{#25333}
Fix dumping of counters in d8.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/721193002

Cr-Commit-Position: refs/heads/master@{#25334}
Soft fail for invalid cache data.

API=ScriptCompiler::CachedData::rejected
LOG=Y
R=vogelheim@google.com, vogelheim@chromium.org

Review URL: https://codereview.chromium.org/724023002

Cr-Commit-Position: refs/heads/master@{#25335}