-> Bool -- True <=> function is overloaded
-> Id -> [LSig Name]
-> TcM (Id, [Located TcSpecPrag])
--- Add INLINE and SPECLIASE pragmas
+-- Add INLINE and SPECIALSE pragmas
-- INLINE prags are added to the (polymorphic) Id directly
-- SPECIALISE prags are passed to the desugarer via TcSpecPrags
-- Pre-condition: the poly_id is zonked