RFR 8239090: Improve CPU feature support in VM_version

[Eric, Chan]

Hi,

Requesting review for

Webrev : http://cr.openjdk.java.net/~phh/8239090/webrev.00/
JBS : https://bugs.openjdk.java.net/browse/JDK-8239090

Yesterday I sent a wrong one, so I send it again,
I improve the “get_processor_features” method by store every cpu features in an enum array so that we don’t have to count how many “%s” that need to added. I passed the tier1 test successfully.

Regards,
Eric Chen