Updates to FFI spec: performGC

[Alastair Reid]

> Do you want a stronger wording on what kind of garbage collection is
> to be performed or do we want to keep it deliberately unspecified
> (ie, leave it to the individual Haskell system)?

It'd be nice to say that it has to be a full GC - but I've no idea how
to specify that in a non-operational (i.e., implementation dependent)
way.  We could insert the word 'full' and leave it to people's
imaginations?

-- 
Alastair Reid                 alastair at reid-consulting-uk.ltd.uk  
Reid Consulting (UK) Limited  http://www.reid-consulting-uk.ltd.uk/alastair/