addForeignPtrFinalizer

[Alastair Reid]

> Actually in the current implementation the finalizers are not
> attached to the ForeignPtr at all: it's the other way around. 

Ah, I see.

Fortunately, I don't think my sketched implementation depended on such
an attachment since it added an attachment of its own.  The design is
intended to sit on top of the current GHC implementation (i.e., one
with Haskell finalizers and no control over the order they are run).

A