treewide: use blas and lapack

This makes packages use lapack and blas, which can wrap different
BLAS/LAPACK implementations.

treewide: cleanup from blas/lapack changes

A few issues in the original treewide:

- can’t assume blas64 is a bool
- unused commented code

pkgs/development/libraries/armadillo/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, cmake, openblasCompat, superlu, hdf5 }:
+{ stdenv, fetchurl, cmake, blas, lapack, superlu, hdf5 }:
 
 stdenv.mkDerivation rec {
   pname = "armadillo";
@@ -10,10 +10,10 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ cmake ];
-  buildInputs = [ openblasCompat superlu hdf5 ];
+  buildInputs = [ blas lapack superlu hdf5 ];
 
   cmakeFlags = [
-    "-DLAPACK_LIBRARY=${openblasCompat}/lib/libopenblas${stdenv.hostPlatform.extensions.sharedLibrary}"
+    "-DLAPACK_LIBRARY=${lapack}/lib/liblapack${stdenv.hostPlatform.extensions.sharedLibrary}"
     "-DDETECT_HDF5=ON"
   ];