Add the missing importlib.test.extension.util.
diff --git a/Lib/importlib/test/extension/util.py b/Lib/importlib/test/extension/util.py
new file mode 100644
index 0000000..d149169
--- /dev/null
+++ b/Lib/importlib/test/extension/util.py
@@ -0,0 +1,21 @@
+import imp
+import os
+import sys
+
+PATH = None
+EXT = None
+FILENAME = None
+NAME = '_testcapi'
+_file_exts = [x[0] for x in imp.get_suffixes() if x[2] == imp.C_EXTENSION]
+try:
+ for PATH in sys.path:
+ for EXT in _file_exts:
+ FILENAME = NAME + EXT
+ FILEPATH = os.path.join(PATH, FILENAME)
+ if os.path.exists(os.path.join(PATH, FILENAME)):
+ raise StopIteration
+ else:
+ PATH = EXT = FILENAME = FILEPATH = None
+except StopIteration:
+ pass
+del _file_exts