Function rustc_incremental::persist::save::save_dep_graph

pub fn save_dep_graph(tcx: TyCtxt<'_>)

Saves and writes the DepGraph to the file system.

This function saves both the dep-graph and the query result cache, and drops the result cache.

This function should only run after all queries have completed. Trying to execute a query afterwards would attempt to read the result cache we just dropped.