RFC: Refactoring SystemABI

[Henry Jen]

Hi,

Please have a look at the webrev[1] refactor the SystemABI APIs based on Mauricio’s proposal. SystemABI is suppose to encapsulate platform-specific details, this patch make NativeInvoker/UpcallHander and CalllingSequence to be implementation details, and thus can further be simplified/removed if we need to. 

The binder suppose to only interact with SystemABI, that’s not completed yet in this webrev, but follow up work should get us there. 

Concept of CallingConvention is introduced as an abstraction for now and is currently simply support default.

Anyway, it’s just first step, and I would like to see if it make sense to us.

Cheers,
Henry

[1] http://cr.openjdk.java.net/~henryjen/panama/SystemABI/webrev/