Channel type should be a template specialization or record

This example shows:
UNIMPLEMENTED: Channel type should be a template specialization or record decl
--> ./typedef_bug.cpp:13:11
|
13 | void bug (chT &inp, chT &o_out)
| ^

Where this completes successfully:
void bug (ac_channel> &inp, ac_channel> &o_out)

This does not:
typedef ac_channel> chT;
void bug (chT &inp, chT &o_out)

untar and adjust XLS_HOME for your env:
./run_xls_bug.sh
[2xls.gz](https://github.com/google/xls/files/11410676/2xls.gz)

Thanks for taking a look