Array documentation is missing its Read instance

[rwbarton]

See http://hackage.haskell.org/package/array-0.5.1.0/docs/Data-Array.html, or the corresponding file from the GHC 7.10.3 binary download.

...
(Ix i, Eq e) => Eq (Array i e)   
(Ix i, Ord e) => Ord (Array i e)     
(Ix a, Show a, Show b) => Show (Array a b)   

But there is also an instance instance (Ix a, Read a, Read b) => Read (Array a b). (It's even documented in the Haskell 2010 Report!)

I'm guessing this is due to the fact that Array and its Eq, Ord and Show instances are defined in module GHC.Arr in base, while the Read instance is defined in module GHC.Read, which imports GHC.Arr. Still the instance really should be documented.

[Blaisorblade]

Based on #297 (comment), this is probably a dup of #372, but with a diagnosis.
This diagnosis appears to match the case of Text in text I mentioned here.

[RyanGlScott]

This was fixed in #724, and will work in the Haddock bundled with GHC 8.4.1. Proof:

[harpocrates]

@alexbiehl Can we close this?

[RyanGlScott]

Indeed we can :)