Set host_arch to ia32 on machines with a 32bit userland but a 64bit kernel.

Set host_arch to ia32 on machines with a 32bit userland but a 64bit kernel.

I don't know if there are any v8 bots with that configuration, but it seems
like a good idea to have v8 be consistent with chromium and nacl here, so that
this works fine if such a bot is ever set up.

This is similar to https://codereview.chromium.org/342493002/ , but with a
detect_v8_host_arch.py script that handles the additional machine types that
standalone.gypi used to handle.

BUG=368384
possibly?
LOG=Y
R=jochen@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=21909

[Nico, 2014-06-18 21:38:40]

http://build.chromium.org/p/tryserver.v8/waterfall seems to ignore my `gcl try`
invocation, but it seems to work locally at least.

[jochen (gone - plz use gerrit), 2014-06-18 22:49:18]

lgtm

[jochen (gone - plz use gerrit), 2014-06-18 22:49:48]

tryserver access is restricted to committers.

Why are you using gcl? You should just "fetch v8" and then use git cl.

[jochen (gone - plz use gerrit), 2014-06-23 08:20:01]

Committed patchset #1 manually as r21909 (presubmit successful).

[jochen (gone - plz use gerrit), 2014-06-23 08:50:02]

On 2014/06/23 at 08:20:01, jochen wrote:
> Committed patchset #1 manually as r21909 (presubmit successful).

broke nacl build...
http://build.chromium.org/p/client.v8/builders/NaCl%20V8%20Linux/builds/2267/...