RFR: updating supports_value_types() method and ACC_Value and ACC_Flattenable flags

[harold seigel]

Hi,

Please review this change to fix method supports_value_types() in 
classFileParser.cpp and to ignore the ACC_Value and ACC_Flattenable 
flags if they are specified in older class file versions.  According to 
the JVM Spec for JDK-10 
<https://docs.oracle.com/javase/specs/jvms/se10/html/index.html>:

    All bits of the access_flags item not assigned in <table> are
    reserved for future use.  They should be set to zero in generated
    class files and *should be ignored by JVM implementations*.

No new tests are needed because this is covered by existing JCK vm tests.

Webrev: 
http://cr.openjdk.java.net/~hseigel/valueTypes_lworld.ACC_flags/webrev/index.html

This webrev was tested with hotspot JTReg tests, many JDK JTReg tests, 
and with vm JCK tests.

Thanks, Harold