review(XXS): 7132945: Tiered: adjust OSR threshold of level 3

[Igor Veresov]

I'd like to adjust one of the thresholds for tiered. Roland and I noticed that setting the value of Tier3BackEdgeThreshold to 60000 instead of 7000 yield far superior startup performance on machines with one CPU. There is no significant change for machines with many cores. 

Webrev: http://cr.openjdk.java.net/~iveresov/7132945/webrev.00/

igor