[project @ 2000-06-30 13:11:07 by simonpj]

In a CCall, a DynamicTarget has a unique that is
used only to generate a uniquely-named typedef.
It should not be used when comparing CCalls (e.g.
when seeing if interface files have changed).
So the main change in this commit is to fix the Eq
instance for PrimOp.CCallTarget, but I took the
opportunity to clean up the CCallTarget interface
a little.