[Transform] Add checks to collapse repeated transform to work only on linear...

[Transform] Add checks to collapse repeated transform to work only on linear segments of graphs with branches

src/finn/transformation/streamline/collapse_repeated.py

@@ -48,9 +48,17 @@ class CollapseRepeatedOp(Transformation):
         graph_modified = False
         for n in graph.node:
             node_ind += 1
-            if n.op_type == self.op_name:
+            if (
+                n.op_type == self.op_name
+                and not model.is_fork_node(n)
+                and not model.is_join_node(n)
+            ):
                 consumer = model.find_consumer(n.output[0])
-                if consumer is not None and consumer.op_type == self.op_name:
+                if (
+                    consumer is not None
+                    and consumer.op_type == self.op_name
+                    and not model.is_join_node(consumer)
+                ):
                     op0_param_name = n.input[1]
                     op1_param_name = consumer.input[1]
                     op0_param = model.get_initializer(op0_param_name)