Function data flow analysis

[em-eight]

Iteratively call #3 until the data flow graph of a function reaches equilibrium

[em-eight]

The iterative function data flow has been implemented, but some improvements can be made from recursive analysis of called functions for better function argument & return value detection. This should not be mandatory for the purposes of https://github.com/em-eight/ppc2cpp/discussions/1

• [ ] Stack creation and register saving detection, and removal of associated instructions from graph
• [ ] Recursively call data flow analysis to called functions to recover arguments and return values