Fix #11: Bootstrapping dmd with ldc

[dukc]

LDC 1.25.0 is now used as the default bootstrap compiler for DMD. Manually tested that the oldest and newest dmd do build. Using DMD as bootstrap still works with an explicit override:

nix-build -E '
let pkgs = import <nixpkgs> {};
dnix = import ./default.nix;
in dnix.packages."${pkgs.system}".dmd-2_105_2.override {buildCompiler = dnix.packages."${pkgs.system}".dmd-binary-2_090_1;}' --show-trace

Why 1.25.0? Because it's dmd equivalent version, 2.095, seems to be the official bootstrap compiler in dmd:s build.d. If you want, you can also explicitly use 1.34.0. According to my tests it compiles 2.105.2 but doesn't compile 2.092.1.

[github-actions]

Thanks for your Pull Request!

Below you will find a summary of the cachix status of each package, for each supported platform.

package	x86_64-linux	x86_64-darwin	aarch64-darwin
dmd	✅ cached	✅ cached	🚫 not supported
dmd-2_092_1	✅ cached	✅ cached	🚫 not supported
dmd-2_096_1	✅ cached	✅ cached	🚫 not supported
dmd-2_098_1	✅ cached	✅ cached	🚫 not supported
dmd-2_100_2	✅ cached	✅ cached	🚫 not supported
dmd-2_102_2	✅ cached	✅ cached	🚫 not supported
dmd-2_103_1	✅ cached	✅ cached	🚫 not supported
dmd-2_104_2	✅ cached	✅ cached	🚫 not supported
dmd-2_105_2	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_079_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_080_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_081_2	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_082_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_083_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_084_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_085_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_086_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_087_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_088_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_089_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_090_1	✅ cached	✅ cached	🚫 not supported
dmd-binary-2_098_0	✅ cached	✅ cached	🚫 not supported
dmd-bootstrap	✅ cached	✅ cached	🚫 not supported
dub	✅ cached	✅ cached	✅ cached
dub-1_30_0	✅ cached	✅ cached	✅ cached
ldc	✅ cached	🚧 known to fail (disabled)	🚧 known to fail (disabled)
ldc-1_30_0	✅ cached	🚧 known to fail (disabled)	🚧 known to fail (disabled)
ldc-binary	✅ cached	✅ cached	✅ cached
ldc-binary-1_19_0	✅ cached	✅ cached	🚫 not supported
ldc-binary-1_25_0	✅ cached	✅ cached	✅ cached
ldc-binary-1_28_0	✅ cached	✅ cached	✅ cached
ldc-binary-1_32_1	✅ cached	✅ cached	✅ cached
ldc-binary-1_34_0	✅ cached	✅ cached	✅ cached

[dukc]

ping @PetarKirov

[dukc]

No review has been given so I'm going ahead and merging as the tests are passing.

@ping PetarKirov post-merge comments still welcome if you wish to leave any.