Variable mangling is unimplemented

[egroge]

When implementing typestates, the compiler creates a hidden variable called _contract_state. This then means that if the writer of a flint program tries to create a variable of the same name in the same scope, there will be an error that they are unable to explain. This issue is not specific to typestates - any local variable created for any reason potentially throws up this naming conflict.

To fix this, variable mangling, whereby variable names are somehow transformed if there is a conflict, should be implemented in both targets. This was previously implemented in move, but it was inconsistent and difficult to work with, so it has been unimplemented to make way for a new mangling design.