Fix sphinx-doc#9194: autodoc: types in typing module are not hyperlinked

This converts types in typing module to valid references when
`autodoc_unqualified_typehints` option enabled.

CHANGES

@@ -43,6 +43,7 @@ Bugs fixed
   with Python 3.10
 * #9968: autodoc: instance variables are not shown if __init__ method has
   position-only-arguments
+* #9194: autodoc: types in types module are not hyperlinked
 * #9947: i18n: topic directive having a bullet list can't be translatable
 * #9878: mathjax: MathJax configuration is placed after loading MathJax itself
 * #9857: Generated RFC links use outdated base url

sphinx/domains/python.py

@@ -83,7 +83,8 @@ class ModuleEntry(NamedTuple):
 def type_to_xref(target: str, env: BuildEnvironment = None, suppress_prefix: bool = False
                  ) -> addnodes.pending_xref:
     """Convert a type string to a cross reference node."""
-    if target == 'None':
+    if target == 'None' or target.startswith('typing.'):
+        # typing module provides non-class types.  Obj reference is good to refer them.
         reftype = 'obj'
     else:
         reftype = 'class'

tests/test_domain_py.py

@@ -348,6 +348,7 @@ def test_parse_annotation(app):
     assert_node(doctree, ([pending_xref, "None"],))
     assert_node(doctree[0], pending_xref, refdomain="py", reftype="obj", reftarget="None")
 
+    # Literal type makes an object-reference (not a class reference)
     doctree = _parse_annotation("typing.Literal['a', 'b']", app.env)
     assert_node(doctree, ([pending_xref, "typing.Literal"],
                           [desc_sig_punctuation, "["],
@@ -356,6 +357,7 @@ def test_parse_annotation(app):
                           desc_sig_space,
                           [desc_sig_literal_string, "'b'"],
                           [desc_sig_punctuation, "]"]))
+    assert_node(doctree[0], pending_xref, refdomain="py", reftype="obj", reftarget="typing.Literal")
 
 
 def test_parse_annotation_suppress(app):