Fix --verify-on-transition for OSR and concurrent sweep.

Fix --verify-on-transition for OSR and concurrent sweep.

Wait for concurrent sweep tasks before verifying points, as building the allocation set expects unmarked objects.

Make assertion okay with a missing stack map at entry, which transiently exists for OSR, as the frame looks the same as unoptimized code here.

Fixes #13608
Fixes #23683
Reproduces issue #26927

R=fschneider@google.com

Committed: https://github.com/dart-lang/sdk/commit/bb85b32d515c0035a38e1145b5dd8e0acd83d71c

[rmacnak, 2016-10-10 21:55:08]

rmacnak@google.com changed reviewers:
+ fschneider@google.com

[Florian Schneider, 2016-10-11 17:08:39]

Lgtm.

[rmacnak, 2016-10-11 22:03:13]

Description was changed from

==========
Fix --verify-on-transition for OSR and concurrent sweep.

Wait for concurrent sweep tasks before verifying points, as building the
allocation set expects unmarked objects.

Make assertion okay with a missing stack map at entry, which transiently exists
for OSR, as the frame looks the same as unoptimized code here.

Fixes #13608
Fixes #23683
Reproduces issue #26927
==========

to

==========
Fix --verify-on-transition for OSR and concurrent sweep.

Wait for concurrent sweep tasks before verifying points, as building the
allocation set expects unmarked objects.

Make assertion okay with a missing stack map at entry, which transiently exists
for OSR, as the frame looks the same as unoptimized code here.

Fixes #13608
Fixes #23683
Reproduces issue #26927

R=fschneider@google.com

Committed:
https://github.com/dart-lang/sdk/commit/bb85b32d515c0035a38e1145b5dd8e0acd83d71c
==========

[rmacnak, 2016-10-11 22:03:14]

Committed patchset #1 (id:1) manually as
bb85b32d515c0035a38e1145b5dd8e0acd83d71c (presubmit successful).