RFR (XS) 8182847: Copy class should use assert macros

[coleen.phillimore at oracle.com]

open webrev at http://cr.openjdk.java.net/~coleenp/8182847.01/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8182847

Tested with tier1-4 on all Oracle platforms in mach5.  Also tested 
failure case with temporary change (see bug for details).

Thanks,
Coleen