fsm_encoding attribute is not passed to Yosys

I am using e97602e68e55273fa11564fbb4388b119c18eeb3
with Yosys `Yosys 0.34+43 (git sha1 d21c464ae, c++ 11.4.0-1ubuntu1~22.04 -fPIC -Os)`
Looks like the following attribute is not passed to Yosys. `(* fsm_encoding="user" *) state_t curr_state ; ` The following example (RTL+Yosys script) illustrates the issue https://drive.google.com/file/d/1227_ul1Q_E0YteFAvkZ7HTWQ5CoVVe7A/view?usp=drive_link
Just change the pointer to the Yosys binary and run `make kiss`. There is no `attribute \fsm_encoding "user"` listed in the output.

Start with the linked RTL and Yosys script, update the Yosys binary pointer, and run `make kiss` to reproduce the missing `fsm_encoding` attribute. Compare the generated output with the expected `attribute \fsm_encoding "user"` and trace the integration path that forwards RTL attributes to Yosys; done means the attribute appears in the output.

Written by the indexing model from the issue text.