Suppressing all DeprecationWarning messages was a bit of a problem for
the -Qwarnall option, so I've changed this to only filter out the one
warning that's a problem in practice.
diff --git a/Lib/test/test___all__.py b/Lib/test/test___all__.py
index 3ed22f9..8a4734c 100644
--- a/Lib/test/test___all__.py
+++ b/Lib/test/test___all__.py
@@ -2,9 +2,6 @@
 import sys
 
 def check_all(modname):
-    import warnings
-    warnings.filterwarnings("ignore", "", DeprecationWarning, modname)
-
     names = {}
     try:
         exec "import %s" % modname in names
@@ -122,6 +119,9 @@
 check_all("random")
 check_all("re")
 check_all("reconvert")
+import warnings
+warnings.filterwarnings("ignore", ".* regsub .*", DeprecationWarning, "regsub",
+                        append=1)
 check_all("regsub")
 check_all("repr")
 check_all("rexec")