lockdep: refactor into non-kernel package

Lockdep doesn't *really* require the kernel package - just the kernel
sources. It's really a user-space tool just compiled from some portable
code within the kernel, nothing more.

Signed-off-by: Austin Seipp <aseipp@pobox.com>

pkgs/os-specific/linux/lockdep/default.nix

@@ -0,0 +1,29 @@
+{ stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+  name    = "lockdep-${version}";
+  version = "3.14";
+
+  src = fetchurl {
+    url = "mirror://kernel/linux/kernel/v3.x/linux-${version}.tar.xz";
+    sha256 = "61558aa490855f42b6340d1a1596be47454909629327c49a5e4e10268065dffa";
+  };
+
+  preConfigure = "cd tools/lib/lockdep";
+  installPhase = ''
+    mkdir -p $out/bin $out/lib $out/include
+
+    cp -R include/liblockdep $out/include
+    make install DESTDIR=$out prefix=""
+
+    substituteInPlace $out/bin/lockdep --replace "./liblockdep.so" "$out/lib/liblockdep.so"
+  '';
+
+  meta = {
+    description = "userspace locking validation tool built on the Linux kernel";
+    homepage    = "https://kernel.org/";
+    license     = stdenv.lib.licenses.gpl2;
+    platforms   = stdenv.lib.platforms.linux;
+    maintainers = [ stdenv.lib.maintainers.thoughtpolice ];
+  };
+}