Add gcc toolchain for arm64/linux

Add gcc toolchain for arm64/linux

This is needed for Chromium builds in debian/arm64
and matches how arm, x86 and x86_64 also have
both clang and gcc toolchains available.

R=brettw@chromium.org, dpranke@chromium.org, scottmg@chromium.org

Committed: https://crrev.com/62c17901df9489112816380771666f4e6857cd59
Cr-Commit-Position: refs/heads/master@{#436267}

[Riku Voipio, 2016-12-02 13:58:14]

PTAL

[Dirk Pranke, 2016-12-02 23:12:31]

lgtm

[Riku Voipio, 2016-12-05 10:40:51]

The CQ bit was checked by riku.voipio@linaro.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-05 10:41:10]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-05 12:27:06]

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

[commit-bot: I haz the power, 2016-12-05 12:27:07]

Dry run: This issue passed the CQ dry run.

[Riku Voipio, 2016-12-05 12:31:36]

The CQ bit was checked by riku.voipio@linaro.org

[commit-bot: I haz the power, 2016-12-05 12:31:55]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-05 12:35:22]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480941096750260, "parent_rev":
"863a9f8e154436c794dc1f3abdd3dcb328f1b880", "commit_rev":
"694ba6e784e7e3da830c88e55c2b106506e70314"}

[commit-bot: I haz the power, 2016-12-05 12:35:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-05 12:38:23]

Description was changed from

==========
Add gcc toolchain for arm64/linux

This is needed for Chromium builds in debian/arm64
and matches how arm, x86 and x86_64 also have
both clang and gcc toolchains available.

R=brettw@chromium.org, dpranke@chromium.org, scottmg@chromium.org
==========

to

==========
Add gcc toolchain for arm64/linux

This is needed for Chromium builds in debian/arm64
and matches how arm, x86 and x86_64 also have
both clang and gcc toolchains available.

R=brettw@chromium.org, dpranke@chromium.org, scottmg@chromium.org

Committed: https://crrev.com/62c17901df9489112816380771666f4e6857cd59
Cr-Commit-Position: refs/heads/master@{#436267}
==========

[commit-bot: I haz the power, 2016-12-05 12:38:24]

Patchset 1 (id:??) landed as
https://crrev.com/62c17901df9489112816380771666f4e6857cd59
Cr-Commit-Position: refs/heads/master@{#436267}