[NaCl SDK] Add arm-nacl-clang support to the SDK

[NaCl SDK] Add arm-nacl-clang support to the SDK

Currently (as with arm-nacl-gcc) there is no testing
done using the produced binaries. I'm working on change
to at least do testing on linux used qemu-arm + sel_lr.

R=binji
BUG=454962
Committed: https://crrev.com/cfcda7eb992c2f6fbd97633ffdf3b5e475ac268b
Cr-Commit-Position: refs/heads/master@{#317261}

[binji, 2015-02-19 23:04:58]

lgtm

[Sam Clegg, 2015-02-20 02:01:09]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2015-02-20 02:01:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/940183002/40001

[commit-bot: I haz the power, 2015-02-20 02:07:04]

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

[commit-bot: I haz the power, 2015-02-20 02:07:05]

Try jobs failed on following builders:
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_gn_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Sam Clegg, 2015-02-20 06:34:15]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2015-02-20 06:35:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/940183002/40001

[commit-bot: I haz the power, 2015-02-20 06:52:23]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-20 06:52:56]

Patchset 3 (id:??) landed as
https://crrev.com/cfcda7eb992c2f6fbd97633ffdf3b5e475ac268b
Cr-Commit-Position: refs/heads/master@{#317261}