RFR: 8199685: Access arraycopy build failure with GCC 7.3.1

[Erik Österlund]

Hi,

Newer compilers are not happy with arraycopy since recent changes made 
RawAccessBarrier accept 5 arguments instead of 3, and there was an 
unused path in Access for HeapWord* arraycopy, that was not expanded, 
that still tried to call an internal arraycopy function with 3 arguments.

The problematic unexpanded overload in RawAccessBarrier for HeapWord* 
addresses has been removed. Instead, the HeapWord logic for performing 
Raw oop arraycopy when it is not known whether compressed oops is used 
or not has been moved to an earlier stage (reduce_types) to better 
reflect how this logic is consistently handled for the other accessors 
with the same HeapWord* logic, to make the code more symmetric.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8199685

Webrev:
http://cr.openjdk.java.net/~eosterlund/8199685/webrev.00/

Thanks,
/Erik