review(XS) 7040485: Use transparent huge page on linux by default

[Igor Veresov]

We should enable the use of transparent huge pages on Linux by default. 
The solution is to set the UseLargePages flag to true by default, but 
try only using UseHugeTLBFS by default if UseLargePages is not specified 
on the command line. We would try both UseSHM and UseHugeTLBFS methods 
if UseLargePages is explicitly set.
This way we maintain compatibility and do not start eating into shared 
memory by default.

Webrev: http://cr.openjdk.java.net/~iveresov/7040485/webrev.00/


Thanks,
igor