multicore tests

[Simon Marlow]

Manuel M T Chakravarty wrote:
> What is involved in making the testsuite and in particular the fast run 
> used in validate to be able to use multiple threads?
> 
> It's quite frustrating to wait around while my CPU is half idle.

See

http://hackage.haskell.org/trac/ghc/ticket/1558

The main problem is the framework failures.  I'm not sure exactly what's 
going on, but IIRC occasionally a GHC gets an unexpected SIGALRM.  Perhaps 
Python isn't turning off its signals when it does fork/exec, or there's a 
race condition somewhere.

The other problem is that there are some bogus ordering assumptions between 
various tests, but these are straightforward to fix.

Cheers,
	Simon