Support Aeson 2.2

[Vekhir]

The Data.Aeson.json functionality was moved to the Data.Aeson.Parser module within attoparsec-aeson. The new package replaces Data.Aeson.Parser for aeson >= 2.2. For aeson <2.2, attoparsec-aeson is an empty package, since the module exists within aeson.

The solution in this PR supports both Aeson < 2.2 and Aeson >= 2.2.

Please release a new version on Hackage once this PR was merged, so the Arch packages can move to Aeson 2.2.

[christiaanb]

@kloonbot run_ci eaf0ac0

[christiaanb]

LGTM

[Vekhir]

Fixed the syntax

[leonschoorl]

@kloonbot run_ci 093ce32

[Vekhir]

We need to help Stack find attoparsec-aeson, so I added that to stack.yaml

[Vekhir]

Apparently, Stackage only has v2.1.0.0

[christiaanb]

@kloonbot run_ci fcf2ce0

[christiaanb]

@kloonbot run_ci a0810dc

[DigitalBrains1]

@kloonbot run_ci 899eff6

[rowanG077]

@kloonbot run_ci 61e37bc

[rowanG077]

@kloonbot run_ci efec0b8

[rowanG077]

@kloonbot run_ci 0871ef4

[DigitalBrains1]

@kloonbot run_ci 2d71558

[DigitalBrains1]

@kloonbot run_ci 1f502af

[leonschoorl]

+  # We can't use newer than 1.12 here: we need singletons 3.x (due to the cabal
+  # file of `clash-testsuite`) but the changed `DConP` constructor in 1.13
+  # stops `singletons-th` from building.
+  doctest = prev.callHackage "doctest" "0.21.1" { };

What package is this comment refering to?
Because doctest doesn't have a 1.12 or 1.13

[rowanG077]

@leon Copy pasted from the other and forgot to change the comment

[leonschoorl]

So th-desugar has a DConP that changed between 1.12 and 1.13, but

clash-compiler/nix/overlay-ghc962.nix

Line 42 in 149885c

th-desugar = prev.th-desugar_1_15;

[DigitalBrains1]

I needed to fix the other comment I promised to fix but didn't. I was going to put it in random-stuff13, I'll add this. So what should the comment be?

[rowanG077]

Comment is coming from the 9.0.2 overlay.

https://github.com/clash-lang/clash-compiler/blob/master/nix/overlay-ghc902.nix#L29-L32C57

This is a good comment:

@DigitalBrains1

# type-errors 0.2.0.2 is bounded on doctest >=0.16.0.1 && <0.22
doctest = prev.callHackage "doctest" "0.21.1" { };

[DigitalBrains1]

@Vekhir, we've just released Clash 1.6.6 with this included!

[Vekhir]

Thank you!