Merge: #17476: make allmethods actually return all methods.

This fixes a regression relative to Python2.  (In 2, methods on a class were
unbound methods and matched the inspect queries being done, in 3 they are just
functions and so were missed).

This is an undocumented function that pydoc itself does not use, but
I found that numpy at least uses it in its documentation generator.

Original patch by Matt Bachmann.

Lib/pydoc.py

@@ -132,7 +132,10 @@ def stripid(text):
     return _re_stripid.sub(r'\1', text)
 
 def _is_some_method(obj):
-    return inspect.ismethod(obj) or inspect.ismethoddescriptor(obj)
+    return (inspect.isfunction(obj) or
+            inspect.ismethod(obj) or
+            inspect.isbuiltin(obj) or
+            inspect.ismethoddescriptor(obj))
 
 def allmethods(cl):
     methods = {}