Update dict_ops.py

Author: BobTheBuidler

mypyc/primitives/dict_ops.py

@@ -125,7 +125,7 @@
 # NOTE: this is currently for internal use only, and not used for CallExpr specialization
 exact_dict_set_item_op = method_op(
     name="__setitem__",
-    arg_types=[dict_rprimitive, object_rprimitive, object_rprimitive],
+    arg_types=[exact_dict_rprimitive, object_rprimitive, object_rprimitive],
     return_type=c_int_rprimitive,
     c_function_name="PyDict_SetItem",
     error_kind=ERR_NEG_INT,