Issue #9260: A finer-grained import lock.

Most of the import sequence now uses per-module locks rather than the
global import lock, eliminating well-known issues with threads and imports.
diff --git a/Lib/test/test_pkg.py b/Lib/test/test_pkg.py
index 4d0eee8..355efe7 100644
--- a/Lib/test/test_pkg.py
+++ b/Lib/test/test_pkg.py
@@ -23,6 +23,8 @@
 def fixdir(lst):
     if "__builtins__" in lst:
         lst.remove("__builtins__")
+    if "__initializing__" in lst:
+        lst.remove("__initializing__")
     return lst