lua: one dso patch to rule them all

We do this same patch in three different ways for four different Lua
versions, even though the structure of the Makefile barely changes
between releases.  We can easily consolidate this by just modifying
the Makefile ourselves instead of using patches (Makefiles are very
amenable to this).

pkgs/development/interpreters/lua-5/default.nix

@@ -1,27 +1,10 @@
 # similar to interpreters/python/default.nix
 { stdenv, lib, callPackage, fetchurl, fetchpatch }:
-let
-  dsoPatch51 = fetchurl {
-    url = "https://projects.archlinux.org/svntogit/packages.git/plain/trunk/lua-arch.patch?h=packages/lua51";
-    sha256 = "11fcyb4q55p4p7kdb8yp85xlw8imy14kzamp2khvcyxss4vw8ipw";
-    name = "lua-arch.patch";
-  };
 
-  dsoPatch52 = fetchurl {
-    url = "https://projects.archlinux.org/svntogit/packages.git/plain/trunk/liblua.so.patch?h=packages/lua52";
-    sha256 = "1by1dy4ql61f5c6njq9ibf9kaqm3y633g2q8j54iyjr4cxvqwqz9";
-    name = "lua-arch.patch";
-  };
-
-in rec {
+rec {
   lua5_4 = callPackage ./interpreter.nix {
     sourceVersion = { major = "5"; minor = "4"; patch = "2"; };
     hash = "0ksj5zpj74n0jkamy3di1p6l10v4gjnd2zjnb453qc6px6bhsmqi";
-    patches = [
-      # build lua as a shared library as well, MIT-licensed from
-      # https://github.com/archlinux/svntogit-packages/tree/packages/lua/trunk
-      ./liblua.so.patch
-    ];
   };
 
   lua5_4_compat = lua5_4.override({
@@ -35,11 +18,6 @@ in rec {
     patches =
       lib.optionals stdenv.isDarwin [ ./5.2.darwin.patch ];
 
-    postConfigure = lib.optionalString (!stdenv.isDarwin) ''
-      cat ${./lua-5.3-dso.make} >> src/Makefile
-      sed -e 's/ALL_T *= */& $(LUA_SO)/' -i src/Makefile
-    '';
-
     postBuild = lib.optionalString (!stdenv.isDarwin) ''
       ( cd src; make $makeFlags "''${makeFlagsArray[@]}" liblua.so )
     '';
@@ -53,7 +31,7 @@ in rec {
   lua5_2 = callPackage ./interpreter.nix {
     sourceVersion = { major = "5"; minor = "2"; patch = "4"; };
     hash = "0jwznq0l8qg9wh5grwg07b5cy3lzngvl5m2nl1ikp6vqssmf9qmr";
-    patches = if stdenv.isDarwin then [ ./5.2.darwin.patch ] else [ dsoPatch52 ];
+    patches = lib.optional stdenv.isDarwin ./5.2.darwin.patch;
   };
 
   lua5_2_compat = lua5_2.override({
@@ -64,7 +42,7 @@ in rec {
   lua5_1 = callPackage ./interpreter.nix {
     sourceVersion = { major = "5"; minor = "1"; patch = "5"; };
     hash = "2640fc56a795f29d28ef15e13c34a47e223960b0240e8cb0a82d9b0738695333";
-    patches = (if stdenv.isDarwin then [ ./5.1.darwin.patch ] else [ dsoPatch51 ])
+    patches = (lib.optional stdenv.isDarwin ./5.1.darwin.patch)
       ++ [ ./CVE-2014-5461.patch ];
   };