Adjust unit test to avoid flakyness when running with the ARM simulator.

Adjust unit test to avoid flakyness when running with the ARM simulator.

In some cases the assert that the test function is not optimized fails
because the function may be optimized already after the second invocation.
(e.g. when running slow in debug mode)
Committed: http://code.google.com/p/v8/source/detail?r=9034

[Jakob Kummerow, 2011-08-29 07:48:29]

LGTM.

We've previously reduced this loop from 5 to 2 iterations due to flakiness, and
at first that seemed to be enough.
If the test is still flaky after this change, we should consider removing the
following assertOptCount(f, 0) and assertIsOptimized(f). In theory they're
correct, but flakiness sometimes defies theory...