RFA: 8043913: remove legacy code in SPARC's VM_Version::platform_features

[Kevin Walls]

Hi,

I'm seeking approval to backport into jdk8u:

8043913: remove legacy code in SPARC's VM_Version::platform_features
https://bugs.openjdk.java.net/browse/JDK-8043913

This is a straight import of the change in 9: 
http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/99995cb1ae44

It removes some getisax() checks and does some reformatting in the 
Solaris SPARC VM_Version code in 
src/os_cpu/solaris_sparc/vm/vm_version_solaris_sparc.cpp.  We're 
presuming we are always on Solaris 10 or later, and this change will 
make further changes in that area more straightforward (there are a 
couple more backports to come...).

Thanks
Kevin