Keep only a single active stack trace, enables traces for thrown non-exceptions

Keep only a single active stack trace, enables traces for thrown non-exceptions

BUG=
R=jmesserly@google.com

Committed: https://github.com/dart-lang/sdk/commit/1ff09b431f19229bfb84e0279851ae09aea60585

[Alan Knight, 2016-12-01 21:30:47]

alanknight@google.com changed reviewers:
+ jmesserly@google.com

[Alan Knight, 2016-12-01 21:30:47]

Just removing the WeakMap seems to work fine and fixes a couple of pending
tests. There are a couple more suppressed tests that seem to be related to when
StackTrace objects get created and the relation to the stack trace stored in
Error objects, but since those don't seem to be blocking things I'm not digging
into them further.

[Jennifer Messerly, 2016-12-01 21:40:21]

lgtm

[Alan Knight, 2016-12-01 21:41:17]

Description was changed from

==========
Keep only a single active stack trace, enables traces for thrown non-exceptions

BUG=
==========

to

==========
Keep only a single active stack trace, enables traces for thrown non-exceptions

BUG=
R=jmesserly@google.com

Committed:
https://github.com/dart-lang/sdk/commit/1ff09b431f19229bfb84e0279851ae09aea60585
==========

[Alan Knight, 2016-12-01 21:41:20]

Committed patchset #1 (id:1) manually as
1ff09b431f19229bfb84e0279851ae09aea60585 (presubmit successful).

[vsm, 2016-12-02 16:50:12]

vsm@google.com changed reviewers:
+ vsm@google.com

[vsm, 2016-12-02 16:50:13]

https://codereview.chromium.org/2545923002/diff/1/pkg/dev_compiler/tool/input...
File pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart
(right):

https://codereview.chromium.org/2545923002/diff/1/pkg/dev_compiler/tool/input...
pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart:560: $_stack
= new Error();
DBC

How about saving the thrown obj also and sanity checking it's the same in
getError below?