[LLVMdev] Enabling the loop vectorizer for -O2 and -Os

[Nadav Rotem]

Hi, 

I enabled the loop vectorizer for -O2 and -Os in r184084.  Please let me know if you are experiencing any regressions. 

Thanks for all the people who contributed, evaluated, measured and reviewed this code.  You are the best!

Thanks,
Nadav