Issue #22869: Split pythonrun into two modules

- interpreter startup and shutdown code moved to a new
  pylifecycle.c module
- Py_OptimizeFlag moved into the new module with the other
  global flags
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index d23b032..d507cfe 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -257,7 +257,7 @@
     Trick so that open won't become a bound method when stored
     as a class variable (as dbm.dumb does).
 
-    See initstdio() in Python/pythonrun.c.
+    See initstdio() in Python/pylifecycle.c.
     """
     __doc__ = DocDescriptor()