liblapack: Add `meta.pkgConfigModules` and test

pkgs/development/libraries/science/math/liblapack/default.nix

···
 , shared ? true
 # Compile with ILP64 interface
 , blas64 ? false
+, testers
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "liblapack";
   version = "3.11";
 
   src = fetchFromGitHub {
     owner = "Reference-LAPACK";
     repo = "lapack";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     sha256 = "sha256-AYD78u70y8cY19hmM/aDjQEzxO8u9lPWhCFxRe5cqXI=";
   };
 
···
 
   postInstall =  let
     canonicalExtension = if stdenv.hostPlatform.isLinux
-                       then "${stdenv.hostPlatform.extensions.sharedLibrary}.${lib.versions.major version}"
+                       then "${stdenv.hostPlatform.extensions.sharedLibrary}.${lib.versions.major finalAttrs.version}"
                        else stdenv.hostPlatform.extensions.sharedLibrary;
   in lib.optionalString blas64 ''
     ln -s $out/lib/liblapack64${canonicalExtension} $out/lib/liblapack${canonicalExtension}
···
 
   checkPhase = ''
     runHook preCheck
-    ctest ${ctestArgs}
+    ctest ${finalAttrs.ctestArgs}
     runHook postCheck
   '';
+
+  passthru.tests.pkg-config = testers.testMetaPkgConfig finalAttrs.finalPackage;
 
   meta = with lib; {
     description = "Linear Algebra PACKage";
     homepage = "http://www.netlib.org/lapack/";
     maintainers = with maintainers; [ markuskowa ];
     license = licenses.bsd3;
+    pkgConfigModules = [ "lapack" ];
     platforms = platforms.all;
   };
-}
+})