VectorAPI testing infrastructure minor fixes

[Halimi, Jean-Philippe]

Dear all,

I have made a quick follow-up patch for the VectorAPI Testing infrastructure. It basically fixes a couple of minor bugs and also enables auto-OS detection in order to accommodate the scripts automatically. I also added a few notes in the README based on the feedback I received. Feel free to review and comment on the following patch:

http://cr.openjdk.java.net/~rlupusoru/panama/webrev_testinginfra_fixes_00/

Thanks,

Jp