fix: TypeErr on python3.9

unsupported operand type(s) for |: '_UnionGenericAlias' and 'types.GenericAlias'

Author: BobTheBuidler

mypyc/irbuild/expression.py

@@ -9,7 +9,7 @@
 import math
 from collections.abc import Sequence
 from functools import partial
-from typing import Callable
+from typing import Callable, Union
 
 from mypy.nodes import (
     ARG_NAMED,
@@ -116,7 +116,7 @@
 from mypyc.primitives.str_ops import str_slice_op
 from mypyc.primitives.tuple_ops import list_tuple_op, tuple_slice_op
 
-ConstantValueTuple = ConstantValue | tuple["ConstantValueTuple", ...]
+ConstantValueTuple = Union[ConstantValue, tuple["ConstantValueTuple", ...]]
 
 # Name and attribute references