feat: adding the asahi configuration

hosts/asahi/apple-silicon-support/packages/mesa-asahi-edge/default.nix

@@ -0,0 +1,44 @@
+{ lib
+, fetchFromGitLab
+, mesa
+}:
+
+(mesa.override {
+  galliumDrivers = [ "softpipe" "llvmpipe" "asahi" ];
+  vulkanDrivers = [ "swrast" "asahi" ];
+}).overrideAttrs (oldAttrs: {
+  version = "25.0.0-asahi";
+  src = fetchFromGitLab {
+    # tracking: https://pagure.io/fedora-asahi/mesa/commits/asahi
+    domain = "gitlab.freedesktop.org";
+    owner = "asahi";
+    repo = "mesa";
+    rev = "asahi-20241211";
+    hash = "sha256-Ny4M/tkraVLhUK5y6Wt7md1QBtqQqPDUv+aY4MpNA6Y=";
+  };
+
+  mesonFlags = let
+    badFlags = [
+      "-Dinstall-mesa-clc"
+      "-Dopencl-spirv"
+      "-Dgallium-nine"
+    ];
+    isBadFlagList = f: builtins.map (b: lib.hasPrefix b f) badFlags;
+    isGoodFlag = f: !(builtins.foldl' (x: y: x || y) false (isBadFlagList f));
+  in (builtins.filter isGoodFlag oldAttrs.mesonFlags) ++ [
+      # we do not build any graphics drivers these features can be enabled for
+      "-Dgallium-va=disabled"
+      "-Dgallium-vdpau=disabled"
+      "-Dgallium-xa=disabled"
+    ];
+
+  # replace patches with ones tweaked slightly to apply to this version
+  patches = [
+    ./opencl.patch
+  ];
+
+  postInstall = (oldAttrs.postInstall or "") + ''
+    # we don't build anything to go in this output but it needs to exist
+    touch $spirv2dxil
+  '';
+})