llvm musl changes

[yu-re-ka]

Description of changes

Musl-specific changes to llvm, that fix some crashes.
For linking some heavier applications (like Firefox) the stack size needs to be increased.
Also some static compiler-runtime libraries are disabled, but are needed for Firefox.
In preparation for #191060 I would like to merge these small changes first, they will also be useful for other bigger applications in pkgsMusl.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.11 Release Notes (or backporting 22.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[yu-re-ka]

I guess this change also leads to a derivation change of llvmPackages_14.lld and thus a few rebuilds:

+  LDFLAGS = lib.optionalString stdenv.hostPlatform.isMusl "-Wl,-z,stack-size=2097152";

When the optionalString condition does to match, it produces a LDFLAGS="";, which is not the same as not having the attribute.