Add initial implementation of importlib. See the NOTES files for what is

planned for the package.

There are no docs yet, but they are coming once the API for the first new
function, importlib.import_module() is finalized.

Lib/importlib/test/frozen/support.py

@@ -0,0 +1,24 @@
+import sys
+
+
+class Null:
+
+    """Just absorb what is given."""
+
+    def __getattr__(self):
+        return lambda *args, **kwargs: None
+
+
+class SilenceStdout:
+
+    """Silence sys.stdout."""
+
+    def setUp(self):
+        """Substitute sys.stdout with something that does not print to the
+        screen thanks to what bytecode is frozen."""
+        sys.stdout = Null()
+        super().setUp()
+
+    def tearDown(self):
+        sys.stdout = sys.__stdout__
+        super().tearDown()