autotools: refactor search paths for aclocal in its own method (#19258)

This commit refactors the computation of the search path
for aclocal in its own method, so that it's easier to reuse
for packages that need to have a custom autoreconf phase.

Co-authored-by: Toyohisa Kameyama <kameyama@riken.jp>

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

@@ -2,10 +2,6 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
-
-from spack import *
-
-
 class Audacious(AutotoolsPackage):
     """A lightweight and versatile audio player."""
 
@@ -27,6 +23,11 @@ class Audacious(AutotoolsPackage):
     depends_on('glib')
     depends_on('qt')
 
+    def patch(self):
+        search_path_args = ' '.join(self.autoreconf_search_path_args)
+        search_path_str = '-I m4 {0}'.format(search_path_args)
+        filter_file('-I m4', search_path_str, 'autogen.sh')
+
     def autoreconf(self, spec, prefix):
         bash = which('bash')
         bash('./autogen.sh')