Function run_core_node 

pub fn run_core_node(
    cx: &mut Cx,
    graph: &Graph,
    plan: &CompiledGraph,
    budget: &mut BudgetLedger,
    cells: &mut TopologyCells,
    nonlinear: &mut TopologyNonlinearState,
    item: &WorkItem,
) -> Result<Vec<VerbAction>>

Runs one built-in topology verb.