Add a couple more tests

Add a couple more tests

These tests were useful for debugging reference_trusted_thread.cc.
Test an easily-forwarded system call, dup().  Also test clone()
directly, in addition to testing it indirectly via pthread_create().
Check for leaked FDs.

Change the test runner to run all tests, even if one fails, rather
than stopping at the first failed test.

[Markus (顧孟勤), 2010-04-26 22:46:24]

LGTM

Nitpick. Are you sure that you don't count the filedescriptors incorrectly. I
would think that you need to filter out "." and ".."

[Mark Seaborn, 2010-04-27 11:35:11]

On 2010/04/26 22:46:24, Markus (顧孟勤) wrote:
> LGTM
>
> Nitpick. Are you sure that you don't count the filedescriptors
> incorrectly. I would think that you need to filter out "."
> and ".."

Yes, it overcounts by 3, but that doesn't matter because it is
only used to check for differences in the number of FDs.  I've
added a comment.

Thanks,
Mark