feat(3p/lisp): Add many packages

Add the following packages along with their transitive dependencies:
- trivial-ldap
- defclass-std
- easy-routes

Change-Id: Ib24517f18d14d57540362132c9a24ff2a5a4bd9d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1336
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: kanepyork <rikingcoding@gmail.com>

third_party/lisp/cl-yacc.nix

@@ -0,0 +1,15 @@
+{ depot, pkgs, ... }:
+
+let src = pkgs.fetchFromGitHub {
+    owner = "jech";
+    repo = "cl-yacc";
+    rev = "1334f5469251ffb3f8738a682dc8ee646cb26635";
+    sha256 = "16946pzf8vvadnyfayvj8rbh4zjzw90h0azz2qk1mxrvhh5wklib";
+  };
+in depot.nix.buildLisp.library {
+  name = "cl-yacc";
+
+  srcs = map (f: src + ("/" + f)) [
+    "yacc.lisp"
+  ];
+}