split writeConstant() into that and writeConstantRaw() for the places
where we don't want OP_CONSTANT written as well.
this caused a bug where doing `"some const string" + x` would cause an
unecessary OP_CONSTANT to be added for the x variable and would cause
the wrong result to be given.
- main: reset stack on repl tick (?)
- chunk: make writeConstant return a ConstantIndex for better
integration with the (optional) OP_CONST_LONG
- compiler: quickfix emitConstant()
- vm: add a global ValueMap
the java part would still fuck me up since it lies on OOP stuff
that zig doesnt provide, so i'm skipping towards the C part of the book
which will hopefully be more understandable from a zig perspective.
Luna