[atomic-primops] casmutarray1 test failure in GHC 7.10

[rrnewton]

As mentioned in #40, this was one of the two tests that failed under GHC 7.10. It needs to be investigated.

[jberryman]

It seems to me this was a testing bug; the code had:

writeArray arr 4 33
 putStrLn "Wrote array elements..."

 tick <- readArrayElem arr 4                        -- TICKET FROM IX 4
 putStrLn$ "(Peeking at array gave: "++show (peekTicket tick)++")"

 (res1,tick2) <- casArrayElem arr 3 tick 44   -- BEING USED ON IX 3
 (res2,_)     <- casArrayElem arr 3 tick 44

When I change the last two lines above to 4 as well the test passes. AFAICT the behavior of the original was undefined and shouldn't be expected to work. If that sounds right I'll close the ticket when I commit.

[rrnewton]

Yes, indeed, that looks like a simple bug in the test! Thanks for catching it.