const runtime.gcDrainIdle

4 uses

	runtime (current package)
		mgc.go#L1295: 				gcDrain(&pp.gcw, gcDrainIdle|gcDrainUntilPreempt|gcDrainFlushBgCredit)
		mgcmark.go#L988: 	gcDrainIdle
		mgcmark.go#L1022: 	idle := flags&gcDrainIdle != 0
		mgcmark.go#L1030: 	if flags&(gcDrainIdle|gcDrainFractional) != 0 {