-typedef enum {
- ThreadEnterGHC, /* enter top thunk on stack */
- ThreadRunGHC, /* return to address on top of stack */
- ThreadEnterInterp, /* enter top thunk on stack (w/ interpreter) */
- ThreadKilled, /* thread has died, don't run it */
- ThreadRelocated, /* thread has moved, link points to new locn */
- ThreadComplete /* thread has finished */
-} StgTSOWhatNext;