parens around RHS of type instance rejected

[ganesh]

This program is accepted by GHC but rejected by HSE:

module Test3 where

class Test3 a

instance (Test3 ())

[nibro]

This is not valid Haskell 98. Nevertheless it was an easy one-line fix, and I prefer too liberal than too strict in cases like this. Fixed in 1.0.1, case closed.