RFR 8212997: [TESTBUG] Remove defmeth tests for class file versions 50 and 51

[Harold David Seigel]

Hi,

Please review this change to remove the defmeth tests for class file 
versions 50 and 51 because these tests are redundant with the defmeth 
tests for class file version 52.  The change removes 320 tests and 
14000+ lines of testing code.

Open Webrev: http://cr.openjdk.java.net/~hseigel/bug_8212997/webrev/

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8212997

The change was tested on Linux X64, Windows, Solaris, and Mac.

Thanks, Harold