migrate php to nix

runtimes/default.nix

@@ -26,4 +26,5 @@ args: {
     "powershell" = import ./powershell.nix args;
     "prolog" = import ./prolog.nix args;
     "ponylang" = import ./ponylang.nix args;
+    "php" = import ./php.nix args;
 }

runtimes/php.nix

@@ -0,0 +1,26 @@
+{pkgs, piston, ...}:
+let
+    pkg = pkgs.php; 
+in piston.mkRuntime {
+    language = "php";
+    version = pkg.version;
+    aliases = [];
+
+    run = ''
+        ${pkg}/bin/php "$@"
+    '';
+
+    tests = [
+        (piston.mkTest {
+            files = {
+                "test.php" = ''
+                    OK
+                '';
+            };
+            args = [];
+            stdin = "";
+            packages = [];
+            main = "test.php";
+        })
+    ];
+}