In preparation for the deprecation of `stdenv.isX`.
These shorthands are not conducive to cross-compilation because they
hide the platforms.
Darwin might get cross-compilation for which the continued usage of `stdenv.isDarwin` will get in the way
One example of why this is bad and especially affects compiler packages
https://www.github.com/NixOS/nixpkgs/pull/343059
There are too many files to go through manually but a treewide should
get users thinking when they see a `hostPlatform.isX` in a place where it
doesn't make sense.
```
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv.is" "stdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv'.is" "stdenv'.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "clangStdenv.is" "clangStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "gccStdenv.is" "gccStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenvNoCC.is" "stdenvNoCC.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "inherit (stdenv) is" "inherit (stdenv.hostPlatform) is"
fd --type f "\.nix" | xargs sd --fixed-strings "buildStdenv.is" "buildStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "effectiveStdenv.is" "effectiveStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "originalStdenv.is" "originalStdenv.hostPlatform.is"
```
During stage 3 of compilation, Zig calls `std.zig.system.darwin.macos.detect`,
which parses /System/Library/CoreServices/.SystemVersionPlatform.plist and
/System/Library/CoreServices/SystemVersion.plist[^1] to determine the OS
version. These paths are inaccessible when the sandbox is enabled, which causes
the build to fail with `OSVersionDetectionFail`[^2]. Fix the build with the
relaxed sandbox option by adding these paths to `__impureHostDeps`.
[^1]: cd62005f19/lib/std/zig/system/darwin/macos.zig
[^2]: https://github.com/NixOS/nixpkgs/issues/287861#issuecomment-2148703491
- migrate it to a dedicated directory, zig/0.12
- can't migrate to by-name
- because of undecipherable darwin.apple_sdk_11_0.callPackage
- nixfmt
- add a simple version test
