Fix sphinx-doc#7119: autodoc: Broken doctree was generated by builtin…

…_resolver

The builtin_resolver() generates broken doctree unexpectedly if it
contains pending_xref_condition nodes.

sphinx/domains/python.py

@@ -1301,6 +1301,10 @@ def istyping(s: str) -> bool:
 
         return s in typing.__all__  # type: ignore
 
+    content = find_pending_xref_condition(node, 'resolved')
+    if content:
+        contnode = content.children[0]
+
     if node.get('refdomain') != 'py':
         return None
     elif node.get('reftype') in ('class', 'obj') and node.get('reftarget') == 'None':