glibc: Use lib.enableFeature and friends

[Ericson2314]

Motivation for this change

Cleaning things up to get them out of the way for #46534.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• 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 nox --run "nox-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)
• Fits CONTRIBUTING.md.

---

[GrahamcOfBorg]

No attempt on x86_64-darwin (full log)

The following builds were skipped because they don't evaluate on x86_64-darwin: glibc

Partial log (click to expand)

Cannot nix-instantiate `glibc' because:
error: while evaluating 'callPackageWith' at /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/lib/customisation.nix:108:35, called from /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/pkgs/top-level/all-packages.nix:9533:11:
while evaluating 'makeOverridable' at /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/lib/customisation.nix:67:24, called from /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/lib/customisation.nix:112:8:
while evaluating anonymous function at /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/pkgs/development/libraries/glibc/default.nix:1:1, called from /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/lib/customisation.nix:69:12:
assertion failed at /private/var/lib/ofborg/builds/repo/38dca4e3aa6bca43ea96d2fcc04e8229/builder/grahamc-ndnd/pkgs/development/libraries/glibc/default.nix:8:1

[GrahamcOfBorg]

Success on x86_64-linux (full log)

Attempted: glibc

Partial log (click to expand)

/nix/store/fg4yq8i8wd08xg3fy58l6q73cjy8hjr2-glibc-2.27

[GrahamcOfBorg]

Success on aarch64-linux (full log)

Attempted: glibc

Partial log (click to expand)

/nix/store/17b1xcgg2l2hyxh39inx6k83c3fzkxfd-glibc-2.27