fixup! fix unexpected '__doc__' values

Author: temyurchenko

astroid/nodes/node_classes.py

@@ -2062,11 +2062,12 @@ def __init__(
             source code. Note: This is after the last symbol.
         """
         if getattr(value, "__name__", None) == "__doc__":
-            raise AssertionError(  # pragma: no cover
+            warnings.warn(  # pragma: no cover
                 "You have most likely called a __doc__ field of some object "
                 "and it didn't return a string. "
                 "That happens to some symbols from the standard library. "
-                "Check for isinstance(<X>.__doc__, str)."
+                "Check for isinstance(<X>.__doc__, str).",
+                RuntimeWarning,
             )
         self.value = value
         """The value that the constant represents."""