some fixes to blas/lapack usage in packages (#1852)

* atlas: fix unit test

* openblas: remove symlinks; use lapack_libs.ld_flags in the test

* mkl: fix openmp variant of blas/lapack libs

* intel-parallel-studio: fix openmp variant of blas/lapack libs

* netlib-scalapack: fix blas/lapack for multilib case (e.g. mkl)

* arpack-ng: fix blas/lapack for multilib case (e.g. mkl)

* petsc: explicitly specify blas/lapack

* minor

* cantera: fix blas/lapack usage

* ipopt: fix blas/lapack usage

* netlib-lapack: fix external blas usage

* mfem: fix lapack/blas usage

* superlu-mt: fix blas usage

* flake8 fixes

var/spack/repos/builtin/packages/arpack-ng/package.py

@@ -88,8 +88,8 @@ def install(self, spec, prefix):
         options.append('-DCMAKE_INSTALL_NAME_DIR:PATH=%s/lib' % prefix)
 
         # Make sure we use Spack's blas/lapack:
-        lapack_libs = spec['lapack'].lapack_libs.joined()
-        blas_libs = spec['blas'].blas_libs.joined()
+        lapack_libs = spec['lapack'].lapack_libs.joined(';')
+        blas_libs = spec['blas'].blas_libs.joined(';')
 
         options.extend([
             '-DLAPACK_FOUND=true',