Prepare for moving nacl_irt_icache definition to the NaCl repository.

Prepare for moving nacl_irt_icache definition to the NaCl repository.

Once nacl_irt_icache has been included in irt.h in the NaCl
repository, Chrome build would fail due to multiple definition error.
This is a change for preparing for the NaCl roll that includes
the NaCl side change.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4033

Committed: https://crrev.com/8ec0c5c4b02b77ca5df6e8c79173901c4a94d568
Cr-Commit-Position: refs/heads/master@{#316461}

[mazda, 2015-02-13 10:17:35]

mazda@chromium.org changed reviewers:
+ dmichael@chromium.org, mseaborn@chromium.org

[mazda, 2015-02-13 10:17:36]

mseaborn@: Could you review the CL?

dmichael@: Could you do an OWNERS review?

Thanks,

[Mark Seaborn, 2015-02-13 16:16:32]

LGTM

[dmichael (off chromium), 2015-02-13 16:32:14]

lgtm

[mazda, 2015-02-16 11:36:01]

The CQ bit was checked by mazda@chromium.org

[commit-bot: I haz the power, 2015-02-16 11:37:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/924783003/1

[commit-bot: I haz the power, 2015-02-16 12:42:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-16 12:43:36]

Patchset 1 (id:??) landed as
https://crrev.com/8ec0c5c4b02b77ca5df6e8c79173901c4a94d568
Cr-Commit-Position: refs/heads/master@{#316461}