Move current_context (formerly cur_frame) into VM struct.
Execution stack is moved from the VM struct to each of execution contexts.
This will be necessary for concurrent execution of two or more contexts in the future.
Factory module is separated from VM module.
Add tests for module (require()), Function and String prototype methods.
This PR is a proposal for refactoring.
current_context
(formerlycur_frame
) intoVM
struct.Factory
module is separated fromVM
module.require()
),Function
andString
prototype methods.