Issue #20763: Fix importlib.machinery.PathFinder to support
PathEntryFinder instances which only define find_module().

Reported by Yukihiro Nakadaira.
diff --git a/Python/importlib.h b/Python/importlib.h
index f55c450..2644b1d 100644
--- a/Python/importlib.h
+++ b/Python/importlib.h
@@ -3365,7 +3365,7 @@
     116,0,0,124,2,0,100,1,0,131,2,0,114,39,0,124,
     2,0,106,1,0,124,1,0,131,1,0,92,2,0,125,3,
     0,125,4,0,110,21,0,124,2,0,106,2,0,124,1,0,
-    131,1,0,125,3,0,100,0,0,125,4,0,124,3,0,100,
+    131,1,0,125,3,0,103,0,0,125,4,0,124,3,0,100,
     0,0,107,9,0,114,85,0,116,3,0,124,1,0,124,3,
     0,131,2,0,83,116,4,0,124,1,0,100,0,0,131,2,
     0,125,5,0,124,4,0,124,5,0,95,5,0,124,5,0,