haskell.compiler.{ghc962,ghcHEAD}: no rendered src on aarch64-linux

This saves just enough space on aarch64-linux so that the hadrian built
GHCs are under the 3GB Hydra output limit:

| compiler | before     | after      | Δ          |
|----------|------------|------------|------------|
| ghc962   | 3241234736 | 2810740560 | -430494176 |
| ghcHEAD  | 3341288328 | 2902760872 | -438527456 |

The total output size can be calculated using (don't forget to use
aarch64-linux):

```
nix-build -A <compiler> | xargs nix path-info -s | awk '{ s += $2 }; END { print s }'
```

pkgs/development/compilers/ghc/common-hadrian.nix

@@ -154,6 +154,8 @@
     ghcSrc = ghcSrc;
     ghcVersion = version;
     userSettings = hadrianUserSettings;
+    # Disable haddock generating pretty source listings to stay under 3GB on aarch64-linux
+    enableHyperlinkedSource = !(stdenv.hostPlatform.isAarch64 && stdenv.hostPlatform.isLinux);
   }
 
 , #  Whether to build sphinx documentation.

pkgs/development/tools/haskell/hadrian/default.nix

@@ -4,6 +4,10 @@
 , extra, filepath, lib, mtl, parsec, shake, text, transformers
 , unordered-containers, cryptohash-sha256, base16-bytestring
 , userSettings ? null
+# Whether to pass --hyperlinked-source to haddock or not. This is a custom
+# workaround as we wait for this to be configurable via userSettings or similar.
+# https://gitlab.haskell.org/ghc/ghc/-/issues/23625
+, enableHyperlinkedSource ? true
 , writeText
 }:
 
@@ -18,6 +22,9 @@ mkDerivation {
   postUnpack = ''
     sourceRoot="$sourceRoot/hadrian"
   '';
+  patches = lib.optionals (!enableHyperlinkedSource) [
+    ./disable-hyperlinked-source.patch
+  ];
   # Overwrite UserSettings.hs with a provided custom one
   postPatch = lib.optionalString (userSettings != null) ''
     install -m644 "${writeText "UserSettings.hs" userSettings}" src/UserSettings.hs

pkgs/development/tools/haskell/hadrian/disable-hyperlinked-source.patch

@@ -0,0 +1,12 @@
+diff --git a/hadrian/src/Settings/Builders/Haddock.hs b/hadrian/src/Settings/Builders/Haddock.hs
+index 902b2f85e2..429a441c3b 100644
+--- a/src/Settings/Builders/Haddock.hs
++++ b/src/Settings/Builders/Haddock.hs
+@@ -57,7 +57,6 @@ haddockBuilderArgs = mconcat
+             , arg $ "--odir=" ++ takeDirectory output
+             , arg $ "--dump-interface=" ++ output
+             , arg "--html"
+-            , arg "--hyperlinked-source"
+             , arg "--hoogle"
+             , arg "--quickjump"
+             , arg $ "--title=" ++ pkgName pkg ++ "-" ++ version