Fasterify ICSlotCache

Fasterify ICSlotCache

Use a hash map instead of a list for faster lookups.

BUG=chromium:517406
LOG=n
R=yangguo@chromium.org

Committed: https://crrev.com/6ea0d55dfb9306200b86e057ac74528321ca709b
Cr-Commit-Position: refs/heads/master@{#30078}

[Jakob Kummerow, 2015-08-08 12:49:35]

The following script generates a test case that on my machine takes 3s before
this CL and 270ms after:

var result = ["(function foo() {"];
for (var i = 0; i < 100000; i++) {
  result.push("  typeof x" + i + ";");
}
result.push("})();");
print(result.join("\n"));

[Jakob Kummerow, 2015-08-08 12:49:45]

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

[commit-bot: I haz the power, 2015-08-08 12:49:54]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1279763006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1279763006/20001

[Yang, 2015-08-08 13:09:33]

On 2015/08/08 12:49:54, commit-bot: I haz the power wrote:
> Dry run: CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1279763006/20001
> View timeline at
>  https://chromium-cq-status.appspot.com/patch-timeline/1279763006/20001

lgtm

[commit-bot: I haz the power, 2015-08-08 13:26:18]

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

[commit-bot: I haz the power, 2015-08-08 13:26:19]

Dry run: This issue passed the CQ dry run.

[Jakob Kummerow, 2015-08-08 16:44:13]

The CQ bit was checked by jkummerow@chromium.org

[commit-bot: I haz the power, 2015-08-08 16:44:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1279763006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1279763006/20001

[commit-bot: I haz the power, 2015-08-08 16:45:27]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-08 16:45:41]

Patchset 2 (id:??) landed as
https://crrev.com/6ea0d55dfb9306200b86e057ac74528321ca709b
Cr-Commit-Position: refs/heads/master@{#30078}