WIP: graalvm 19.2.1 -> 20.0.0 (plus some refactoring)

[hlolli]

Motivation for this change

Requested update and refactor #83080

Rebased on this pending PR #85902

Things done

Still WIP, feel free to give feedback. As of this writing I've only compiled the sdk (core) of graalvm for java8. Java11 support should be much easier. As well as splitting some of the modules (FastR/graal-js/GraalRuby etc) as this is too much for 1 person to maintain.

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[ericdallo]

I think we should close this PR, it was already updated

[taku0]

graalvm8, not graalvm8-ce or graalvm8-ee, is not updated. graalvm8-ce and graalvm8-ee are binary packages while graalvm8 builds from the source.

[hlolli]

good points here. I'm keeping the branch. There was a problem with the embedded llvm compiler in the prebuilt sources. If that isn't resolved in the near future, I will continue this work. I'm still waiting for the java PR to be merged #85902 (I see now that it needs rebase), but without the static java, building graalvm from sources wont work. Must admit that in the end, it was bit demotivating that it took so much time for reviews and I had put a lot of hours in this (which is why I'm bit burnt from the graalvm from sources and happy to see the prebuilts working mostly).