Request for reviews: 7188176: The JVM should differentiate between T and M series and adjust GC ergonomics

[Tao Mao]

7188176: The JVM should differentiate between T and M series and adjust 
GC ergonomics

webrev:
http://cr.openjdk.java.net/~twisti/7188176/ 
<http://cr.openjdk.java.net/%7Etwisti/7188176/>

The code has been tested on real M-series machine. In the testing, it 
was able to recognize the M-series machine and do the correct 
calculation of GCThreads.

Thanks.
Tao Mao