shoehorn unittest async results into python test result interpretation

Author: RonnyPfannschmidt

src/_pytest/python.py

@@ -194,10 +194,14 @@ def pytest_pyfunc_call(pyfuncitem: "Function"):
     funcargs = pyfuncitem.funcargs
     testargs = {arg: funcargs[arg] for arg in pyfuncitem._fixtureinfo.argnames}
     result = testfunction(**testargs)
-    if (
-        hasattr(result, "__await__") or hasattr(result, "__aiter__")
-    ) and not async_ok_in_stdlib:
-        async_warn(pyfuncitem.nodeid)
+    if hasattr(result, "__await__") or hasattr(result, "__aiter__"):
+        if async_ok_in_stdlib:
+            # todo: investigate moving this to the unittest plugin
+            #       by a test call result hook
+            testcase = testfunction.__self__
+            testcase._callMaybeAsync(lambda: result)
+        else:
+            async_warn(pyfuncitem.nodeid)
     return True