RFR 8235513: Change JVM to check for preview features using JVM_CLASSFILE_MAJOR_VERSION

[Harold Seigel]

Hi,

Please review this small change to use JVM_CLASSFILE_MAJOR_VERSION 
instead of 58 when checking that a class file using a preview feature 
has the right major class file version.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8235513/webrev/index.html

JBS Bug: http://cr.openjdk.java.net/~hseigel/bug_8235513/webrev/index.html

The fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-x64, Solaris, Windows, and Mac OS X and JCK lang and VM 
tests on Linux-x64. Additional testing of Mach5 tiers 3-5 tests on 
Linux-x64 is in progress.

Thanks, Harold