RFR: JDK-8231499: Shenandoah: compiler/arraycopy/TestDefaultMethodArrayCloneDeoptC2 fails

[Roman Kennke]

Recent arraycopy changes breaks compilation of C2 arraycopy intrinsic. 
It fails silently, so you only notice degradation of performance.

Apparently the register allocator barfs on the 4 arguments (I suppose 
sending both the address and the base of that address is a little bit 
funny).

Fix is to fall back to what Aleksey original proposed and only send src 
and dst object base pointer, and let runtime figure out the rest.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8231499
Webrev:
http://cr.openjdk.java.net/~rkennke/JDK-8231499/webrev.00/

Testing: hotspot_gc_shenandoah (x86_64 and x86_32) and testcase that is 
provided in the bug report, all pass.

Ok?

Roman