handle create pattern when expr is not an Expression/Atom

Author: mmatera

mathics/core/pattern.py

@@ -83,6 +83,8 @@ def create(expr: BaseElement) -> "Pattern":
         Otherwise, if ``expr`` is an ``Atom``, create and return  ``AtomPattern`` for ``expr``.
         Otherwise, create and return and ``ExpressionPattern`` for ``expr``.
         """
+        if not isinstance(expr, (Atom, Expression)):
+            expr = expr.to_expression()
 
         name = expr.get_head_name()
         pattern_object = pattern_objects.get(name)