haskell: ghcjs shims: dc034a0 -> b970152

[ljli]

haskell.compiler.ghcjs is currently broken due to tasty-ant-xml, where we are waiting for a newer version to be picked up by hackage2nix.
But haskell.compiler.ghcjsHEAD builds and of course I tested ghcjs with a fewer other local fixes.

Motivation for this change

There are some important fixes in there. I was bitten in particular by wrongly translated file permissions in the base shim, which is fixed now.

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

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[mention-bot]

@ljli, thanks for your PR! By analyzing the history of the files in this pull request, we identified @waern and @cstrahan to be potential reviewers.