New package: GNDS (#27176)

Adds a new package for the AMPX/SCALE implementation of the GNDS
interface,
https://www.oecd.org/publications/specifications-for-the-generalised-nuclear-database-structure-gnds-94d5e451-en.htm
.

var/spack/repos/builtin/packages/gnds/package.py

@@ -0,0 +1,28 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Gnds(CMakePackage):
+    """The GNDS package is an implementation of the OECD specifications for the
+    Generalized Nuclear Database Structure used in the AMPX cross section
+    processing code.
+    """
+
+    homepage = "https://code.ornl.gov/RNSD/gnds"
+    url      = "https://code.ornl.gov/RNSD/gnds/-/archive/v0.0.1/gnds-v0.0.1.tar.gz"
+
+    maintainers = ['sethrj']
+
+    version('0.0.1', sha256='4c8faaa01a3e6fb08ec3e8e126a76f75b5442509a46b993e325ec79dd9f04879')
+
+    variant('shared', default=True, description="Build shared libraries")
+
+    depends_on('pugixml')
+
+    def cmake_args(self):
+        args = [self.define_from_variant('BUILD_SHARED_LIBS', 'shared')]
+        return args