Function vm_outcome_concurrent 

pub fn vm_outcome_concurrent(source: &str) -> RunOutcome

The VM outcome for a CONCURRENT program — drives the bytecode VM on the cooperative scheduler (VmTask on run_with_seed, seed 0) exactly as the browser/playground does, so a Pipe/task/ Select program runs on the VM byte-identical to the tree-walker’s async path. The plain vm_outcome errors on any concurrency op (requires the scheduler driver); this is the oracle the AOT concurrency lock compares against so tw == VM == AOT is verifiable for the concurrent set.