Convert libatomic-ops to AutotoolsPackage (#3540)

var/spack/repos/builtin/packages/libatomic-ops/package.py

@@ -25,7 +25,7 @@
 from spack import *
 
 
-class LibatomicOps(Package):
+class LibatomicOps(AutotoolsPackage):
     """This package provides semi-portable access to hardware-provided
     atomic memory update operations on a number architectures."""
 
@@ -34,9 +34,5 @@ class LibatomicOps(Package):
 
     version('7.4.4', '426d804baae12c372967a6d183e25af2')
 
-    def install(self, spec, prefix):
-        configure('--prefix={0}'.format(prefix),
-                  '--enable-shared')
-
-        make()
-        make('install')
+    def configure_args(self):
+        return ['--enable-shared']