Vars do not survive Edaflow

[psi-chuffine]

Any variables added to a flow with commands.add_var do not survive to the output in Edaflow.py

Should

# This is an input node. Inject dependency on pre_build scripts
if not node.deps:
    # Inject pre-build scripts before the first command
    # that the node executes. Note that this isn't
    # technically correct since the first command in
    # the list might not be the first command executed
    node.inst.commands.commands[0].order_only_deps = ["pre_build"]
self.commands.commands += node.inst.commands.commands

include self.commands.vars += node.inst.commands.vars at the end?