(Merge 3.2) Issue #13628: python-gdb.py is now able to retrieve more frames in
the Python traceback if Python is optimized.

 * delay the lookup of the size_t type, it is not available at startup
 * The second argument of the PyFrameObjectPtr constructor is optional, as
   done in other constructors
 * iter_builtins() and iter_globals() methods of PyFrameObjectPtr returns
   an empty tuple instead of None if Python is optimized
 * Fix py-bt and py-bt-full to handle correctly "optimized" frames
 * Frame.get_pyop() tries to get the frame pointer from PyEval_EvalCodeEx()
   if the pointer is optimized out in PyEval_EvalFrameEx()
diff --git a/Misc/NEWS b/Misc/NEWS
index e04ae7a..aeb1c89 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -423,7 +423,7 @@
   choose the cipher based on their own preferences, rather than on the
   client's.
 
-- Issue #11813: Fix inspect.getattr_static for modules. Patch by Andreas 
+- Issue #11813: Fix inspect.getattr_static for modules. Patch by Andreas
   Stührk.
 
 - Issue #7502: Fix equality comparison for DocTestCase instances.  Patch by
@@ -1692,6 +1692,9 @@
 Tools/Demos
 -----------
 
+- Issue #13628: python-gdb.py is now able to retrieve more frames in the Python
+  traceback if Python is optimized.
+
 - Issue #11996: libpython (gdb), replace "py-bt" command by "py-bt-full" and
   add a smarter "py-bt" command printing a classic Python traceback.