Remove unused is_class_scope bit from Scope and ScopeInfo

Remove unused is_class_scope bit from Scope and ScopeInfo

This was added in https://chromium.googlesource.com/v8/v8/+/4a709dd65,
but the only check for it that remained in the final patch is inside
a DCHECK. It appears that the approach for checking use of class names
in methods evolved quite a bit over the review of the original patch.

Committed: https://crrev.com/e334410340e6ec1a7439b82705e1b65591d3062d
Cr-Commit-Position: refs/heads/master@{#29428}

[adamk, 2015-06-30 23:12:45]

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

[adamk, 2015-06-30 23:12:50]

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

[commit-bot: I haz the power, 2015-06-30 23:13:06]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219993002/1

[commit-bot: I haz the power, 2015-06-30 23:41:42]

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

[commit-bot: I haz the power, 2015-06-30 23:41:43]

Dry run: This issue passed the CQ dry run.

[rossberg, 2015-07-01 17:16:49]

I'd have to check, this might have been a preparatory addition for yet missing
class scoping checks in strong mode that Marja couldn't finish. I plan to take
that up in a while. But I suppose we can always revert the removal later, so
LGTM.

[adamk, 2015-07-01 17:18:44]

On 2015/07/01 17:16:49, rossberg wrote:
> I'd have to check, this might have been a preparatory addition for yet missing
> class scoping checks in strong mode that Marja couldn't finish. I plan to take
> that up in a while. But I suppose we can always revert the removal later, so
> LGTM.

Sorry for the churn if it is indeed useful in the future, but it should be
simple enough (I ran into this when I was looking for options to fix the
debugger's view of scopes created only for desugaring).

[adamk, 2015-07-01 17:18:50]

The CQ bit was checked by adamk@chromium.org

[commit-bot: I haz the power, 2015-07-01 17:19:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219993002/1

[commit-bot: I haz the power, 2015-07-01 17:20:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-01 17:21:16]

Patchset 1 (id:??) landed as
https://crrev.com/e334410340e6ec1a7439b82705e1b65591d3062d
Cr-Commit-Position: refs/heads/master@{#29428}