RFR (14) 8236769: Clarify javadoc of memory access API

[Chris Hegarty]

> On 8 Jan 2020, at 15:33, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
> 
> I've looked at the java.lang.constant.ClassDesc interface which is similar in spirit to what MemoryLayout does: an interface that is not meant to be implemented by the user. There are many default methods there, and no implSpec, except for displayName() (to describe what the implementation does).
> 
> I'm really on the fence for byteAlignment() as the method javadoc is already clear enough about what the method does?

I would be fine with dropping the implSpec - just adding the new clarifying wording as “regular” normative spec.

-Chris.