Hotfix to make clang-by-default work with gcc 4.8

Hotfix to make clang-by-default work with gcc 4.8

A better fix is to set clang further up, so that gcc_version is set to
0 when clang is on automatically
( https://codereview.chromium.org/384633005 ). This is however blocked
on nacl also using the "clang" symbol, so that needs to be fixed first
( https://codereview.chromium.org/384793002 ). To make the build go for
people in the meantime, land this hack. I'll revert it once the nacl change has
landed in nacl and then rolled into chromium, and the better fix has landed.

BUG=360311
TBR=thestig@chromium.org
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=282377

[tonikitoo_, 2014-07-10 17:32:54]

On 2014/07/10 17:26:39, Nico (away) wrote:

informal lgtm

[Nico, 2014-07-10 17:40:55]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-07-10 17:42:14]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/379693003/1

[Nico, 2014-07-10 17:58:17]

The CQ bit was unchecked by thakis@chromium.org

[Nico, 2014-07-10 17:58:36]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-07-10 18:00:04]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/379693003/1

[commit-bot: I haz the power, 2014-07-10 18:02:04]

Change committed as 282377