RFR: 8079203: aarch64: need to cater for different partner implementations

[Edward Nevill]

Hi,

The following webrev addresses issue
http://bugs.openjdk.java.net/browse/JDK-8079203

http://cr.openjdk.java.net/~enevill/8079203/webrev

The patch parses /proc/cpuinfo to obtain cpu, model, variant and revision
information.

This information is used to drive C1 & C2 code generation for minor
differences in implementation.

Please review and if approved I will push,

Thanks,
Ed.