Lower the number of threads for some threading tests when testing on ARM to avoid timeouts

Lower the number of threads for some threading tests when testing on ARM to avoid timeouts

R=ricow@chromium.org

BUG=none
TEST=cctest/test-lockers/LockerUnlocker,cctest/test-lockers/LockTwiceAndUnlock,cctest/test-lockers/SeparateIsolatesLocksNonexclusive

Committed: http://code.google.com/p/v8/source/detail?r=8597

[Rico, 2011-07-11 11:59:56]

LGTM, is there a reason why this started timing out now?

[Søren Thygesen Gjesse, 2011-07-11 12:16:41]

On 2011/07/11 11:59:56, Rico wrote:
> LGTM, is there a reason why this started timing out now?

Not that I can find. If I run on the tegra2 test boards they also hang with 100
threads before the last push to trunk. I did not mention that in the commit
message, but the tests hang with 100 threads. If they succeed they take less
than 1 sec. On the tegra2 test boards the limit is between 75 and 90 threads.