fn symbol(&mut self, name: SharedSymbol, span: Span) -> SST {
        // if we are hoisting the variable,
        // mark the variable as being used before its lexical
        // definition
        return SST::Base(Base::Symbol(self.resolve_symbol(name, span)));
    }
Replaces a symbol name with a unique identifier for
that symbol
passerine/src/compiler/hoist.rs