[strong] Implement revised strong class semantics

[strong] Implement revised strong class semantics

Weak classes can inherit from strong ones again, a strong base class makes
instances strong.

BUG=v8:3956
LOG=N

Committed: https://crrev.com/24ec2a0baae57dc9f6e1dfce7c5bdf30ea8c791d
Cr-Commit-Position: refs/heads/master@{#30867}

[conradw, 2015-09-17 14:16:11]

conradw@chromium.org changed reviewers:
+ rossberg@chromium.org

[conradw, 2015-09-17 14:16:11]

PTAL

[rossberg, 2015-09-22 15:26:28]

lgtm

LGTM modulo comment

https://codereview.chromium.org/1347243004/diff/1/test/mjsunit/strong/class-l...
File test/mjsunit/strong/class-literals.js (right):

https://codereview.chromium.org/1347243004/diff/1/test/mjsunit/strong/class-l...
test/mjsunit/strong/class-literals.js:118: (function
MonkeyPatchedClassLiterals() {
Maybe add cases that change from StrongClassWeak/StrongInstances to
StrongClassStrong/WeakInstances? You only need one extra weak class in the
middle, I think.

[conradw, 2015-09-22 16:30:34]

The CQ bit was checked by conradw@chromium.org

[conradw, 2015-09-22 16:30:34]

The patchset sent to the CQ was uploaded after l-g-t-m from
rossberg@chromium.org
Link to the patchset: https://codereview.chromium.org/1347243004/#ps20001
(title: "\cl feedback")

[commit-bot: I haz the power, 2015-09-22 16:30:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1347243004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1347243004/20001

[commit-bot: I haz the power, 2015-09-22 16:34:47]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-22 16:35:06]

Patchset 2 (id:??) landed as
https://crrev.com/24ec2a0baae57dc9f6e1dfce7c5bdf30ea8c791d
Cr-Commit-Position: refs/heads/master@{#30867}