[test] Make test duplication more robust

[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238
Committed: https://crrev.com/04bda550c26e10624db016e8362849044d771483
Cr-Commit-Position: refs/heads/master@{#38373}

[Michael Achenbach, 2016-08-05 10:07:37]

Description was changed from

==========
[test] Make test duplication more robust

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

to

==========
[test] Make test duplication more robust

BUG=v8:5238
==========

[Michael Achenbach, 2016-08-05 10:07:37]

machenbach@chromium.org changed reviewers:
+ jkummerow@chromium.org, tandrii@chromium.org

[Michael Achenbach, 2016-08-05 10:10:54]

Description was changed from

==========
[test] Make test duplication more robust

BUG=v8:5238
==========

to

==========
[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238
==========

[Michael Achenbach, 2016-08-05 10:12:18]

PTAL. Measured with cProfile. This gives a small perf improvement on top of
additional robustness.

[Michael Achenbach, 2016-08-05 10:12:35]

The CQ bit was checked by machenbach@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-05 10:12:43]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[tandrii(chromium), 2016-08-05 10:25:48]

lgtm

[commit-bot: I haz the power, 2016-08-05 10:33:40]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-08-05 10:33:41]

Dry run: This issue passed the CQ dry run.

[Jakob Kummerow, 2016-08-05 11:00:02]

lgtm

[Michael Achenbach, 2016-08-05 11:47:40]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2016-08-05 11:47:46]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-05 11:51:23]

Description was changed from

==========
[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238
==========

to

==========
[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238
==========

[commit-bot: I haz the power, 2016-08-05 11:51:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-05 11:51:40]

Description was changed from

==========
[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238
==========

to

==========
[test] Make test duplication more robust

This makes test outcomes immutable. This has two benefits:
1) It's more robust. Using the |= operator by mistake
wouldn't lead to unwanted mutation.
2) It's faster as now the set reference can be copied again
when copying test cases. Test case copying happens an order
of magnitude more often than rules do apply.

BUG=v8:5238

Committed: https://crrev.com/04bda550c26e10624db016e8362849044d771483
Cr-Commit-Position: refs/heads/master@{#38373}
==========

[commit-bot: I haz the power, 2016-08-05 11:51:41]

Patchset 1 (id:??) landed as
https://crrev.com/04bda550c26e10624db016e8362849044d771483
Cr-Commit-Position: refs/heads/master@{#38373}