Do not look for the slot in the ScopeInfo's global range when it's not necessary.

Do not look for the slot in the ScopeInfo's global range when it's not necessary.

This fixes the Runtime_DeclareGlobals performance regression caused by a huge number of global var declarations mentioned in chromium:517778.

BUG=chromium:517778
LOG=N

Committed: https://crrev.com/a1c1e2bd44ca4f5381c47b34be7648e94bf775d7
Cr-Commit-Position: refs/heads/master@{#30679}

[Igor Sheludko, 2015-09-10 12:28:54]

ishell@chromium.org changed reviewers:
+ bmeurer@chromium.org

[Igor Sheludko, 2015-09-10 12:28:55]

The CQ bit was checked by ishell@chromium.org

[Igor Sheludko, 2015-09-10 12:28:55]

PTAL

[Igor Sheludko, 2015-09-10 12:29:02]

The CQ bit was unchecked by ishell@chromium.org

[Benedikt Meurer, 2015-09-10 12:33:56]

LGTM. I like it!

[Igor Sheludko, 2015-09-10 12:34:50]

The CQ bit was checked by ishell@chromium.org

[commit-bot: I haz the power, 2015-09-10 12:35:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1335633002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1335633002/20001

[commit-bot: I haz the power, 2015-09-10 12:55:01]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-10 12:55:10]

Patchset 2 (id:??) landed as
https://crrev.com/a1c1e2bd44ca4f5381c47b34be7648e94bf775d7
Cr-Commit-Position: refs/heads/master@{#30679}