haskell.compiler.ghc884: revert to reverse bootstraping using 8.10.2

Reverse bootstrapping is not supported by GHC upstream. In the case of
8.8.4 it just happens to work using 8.10.2, with later versions,
specifically 8.10.7 there seems to be some digressions in the generated /
used C code which cause 8.8.4 to fail to compile [1].

Thus we revert to using 8.10.2 for aarch64 and Musl which means: Still
no integer-simple and musl at the same time (however all other GHCs have
it, so it's probably not a problem) and no aarch64-darwin (GHC 8.8.4
can't target that architecture anyways). In short, the situation stays
the same.

[1]: https://github.com/NixOS/nixpkgs/pull/138523#issuecomment-927339953

pkgs/development/compilers/ghc/8.8.4.nix

@@ -346,6 +346,11 @@ stdenv.mkDerivation (rec {
     ] ++ lib.teams.haskell.members;
     timeout = 24 * 3600;
     inherit (ghc.meta) license platforms;
+    # integer-simple builds are broken with musl when bootstrapping using
+    # GHC 8.10.2 and below, however it is not possible to reverse bootstrap
+    # GHC 8.8.4 with GHC 8.10.7.
+    # See https://github.com/NixOS/nixpkgs/pull/138523#issuecomment-927339953
+    broken = hostPlatform.isMusl && enableIntegerSimple;
   };
 
   dontStrip = (targetPlatform.useAndroidPrebuilt || targetPlatform.isWasm);

pkgs/top-level/haskell-packages.nix

@@ -73,10 +73,9 @@ in {
     ghc884 = callPackage ../development/compilers/ghc/8.8.4.nix {
       bootPkgs =
         # aarch64 ghc865Binary gets SEGVs due to haskell#15449 or similar
-        # the oldest ghc with aarch64-darwin support is 8.10.5
         # Musl bindists do not exist for ghc 8.6.5, so we use 8.10.* for them
         if stdenv.isAarch64 || stdenv.hostPlatform.isMusl then
-          packages.ghc8107BinaryMinimal
+          packages.ghc8102BinaryMinimal
         else
           packages.ghc865Binary;
       inherit (buildPackages.python3Packages) sphinx;