Revert "[heap] Add TSAN suppression for lock-order inversion in Scavenger"

This reverts commit e26cd874.

Reason for revert: The issue has been fixed. See related bug for description and CLs.

Original change's description:
> [heap] Add TSAN suppression for lock-order inversion in Scavenger
> 
> The Scavenger currently requires taking the lock for OLD->NEW processing
> and can also take another lock for sweeping a different page.
> 
> Since order of pages during scavenge and sweep is unstable this may
> result in lock order inversion reports on TSAN when long-running
> programms are only executed on a single thread.
> 
> The report is a false positve, hence flag it as suppression until we
> redesign this particular piece.
> 
> No-try: true
> Bug: v8:6923
> Change-Id: I82355be1c8d83ea61cc21152aeb10b58b1dc4b86
> Reviewed-on: https://chromium-review.googlesource.com/716261
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#48504}

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:6923
Change-Id: I7711466c6e2175dcab8d64d6a642e458e1cde3f5
Reviewed-on: https://chromium-review.googlesource.com/738110Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48913}

tools/sanitizers/tsan_suppressions.txt

@@ -4,6 +4,3 @@
 # Incorrectly detected lock cycles in test-lockers
 # https://code.google.com/p/thread-sanitizer/issues/detail?id=81
 deadlock:LockAndUnlockDifferentIsolatesThread::Run
-
-# https://bugs.chromium.org/p/v8/issues/detail?id=6923
-deadlock:v8::internal::ScavengingTask::RunInParallel
\ No newline at end of file