Fix up bzip2 install

lib/spack/llnl/util/filesystem.py

@@ -30,6 +30,7 @@
 import sys
 import re
 import shutil
+import stat
 import errno
 import getpass
 from contextlib import contextmanager, closing
@@ -145,6 +146,13 @@ def install(src, dest):
     shutil.copy(src, dest)
     set_install_permissions(dest)
 
+    src_mode = os.stat(src).st_mode
+    dest_mode = os.stat(dest).st_mode
+    if src_mode | stat.S_IXUSR: dest_mode |= stat.S_IXUSR
+    if src_mode | stat.S_IXGRP: dest_mode |= stat.S_IXGRP
+    if src_mode | stat.S_IXOTH: dest_mode |= stat.S_IXOTH
+    os.chmod(dest, dest_mode)
+
 
 def expand_user(path):
     """Find instances of '%u' in a path and replace with the current user's