Support new call interface

[axic]

• return values have been changed
• return value isn't written to be a paramater but retrieved via returndatacopy

[lrettig]

Cf:

• Propose RETURNDATACOPY and RETURNDATASIZE. ethereum/EIPs#211
• https://github.com/ethereum/EIPs/blob/master/EIPS/eip-211.md
• EEI: calls and return data design#70
• EEI: call* do not use a result offset, rather rely on returnDataCopy to access it design#74

[lrettig]

Need to add:

• RETURNDATASIZE
• RETURNDATACOPY

(Cf. https://github.com/ethereum/ethereumj/pull/919/files#diff-e2305a94a8fe46fe43860fc9ed6a5eacR789)

Need to update:

• CALL (call)
• CALLCODE (callCode)
• DELEGATECALL (callDelegate)
• CALLSTATIC (callStatic to be added in Support Byzantium opcodes #163)

[lrettig]

@axic: to be clear, the CREATE opcode and EEI methods have not changed--it's just that they clear the return data buffer, right? So CREATE does not need to change in evm2wasm, since this will happen at a lower level, right?

[axic]

CALLSTATIC (callStatic to be added in #163)

This is actually called STATICCALL in EVM.

to be clear, the CREATE opcode and EEI methods have not changed--it's just that they clear the return data buffer, right?

Yeah actually CREATE doesn't need to be changed.