Missing parentheses and backticks

In several cases, GHC does not output parentheses or backticks in error messages. For example, compiling this contrived file

data A = (:&&) Int Int | A Int Int

x (+) ((&)@z) ((:&&) a b) (c :&& d) (e `A` f) (A g h) = y
  where infixl 3 `y`
        y _ = (&)
        {-# INLINE (&) #-}
        {-# SPECIALIZE (&) :: a #-}
        (&) = x

gives an error message containing:

x + (&@z) (:&& a b) (c :&& d) (e A f) (A g h)
  = y
  where
      infixl 3 y
      y _ = (&)
      {-# INLINE & #-}
      {-# SPECIALIZE & :: a #-}

Attached patch fixes this issue in several places.

Trac metadata

Trac field	Value
Version	7.6.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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