transitive imports & hiding

[Ross Paterson]

With these modules:

	module A(function, Class(method)) where
	function = id
	class Class a where method :: a

	module B(function, Class(..)) where
	import A

	module C where
	import B hiding (function)
	f = method

hugs C.hs yields
ERROR "C.hs":3 - Undefined variable "method"