allegro5: split outputs -> out, dev; add fixDarwinDylibNames (#398651)

pkgs/development/libraries/allegro/5.nix

@@ -4,6 +4,7 @@
   cmake,
   enet,
   fetchFromGitHub,
+  fixDarwinDylibNames,
   flac,
   freetype,
   gtk3,
@@ -49,10 +50,14 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-agE3K+6VhhG/LO52fiesCsOq1fNYVRhdW7aKdPCbTOo=";
   };
 
-  nativeBuildInputs = [
-    cmake
-    pkg-config
-  ];
+  nativeBuildInputs =
+    [
+      cmake
+      pkg-config
+    ]
+    ++ lib.optionals stdenv.hostPlatform.isDarwin [
+      fixDarwinDylibNames
+    ];
 
   buildInputs =
     [
@@ -100,6 +105,11 @@ stdenv.mkDerivation rec {
 
   cmakeFlags = [ "-DCMAKE_SKIP_RPATH=ON" ];
 
+  outputs = [
+    "out"
+    "dev"
+  ];
+
   meta = with lib; {
     description = "Game programming library";
     homepage = "https://liballeg.org/";