Remove iota template function & last call site.

Nice function, but with just one place using it in 9 years best
coded verbatim at the call site...

Change-Id: Ib306cf2311a39299cb007441c7cb1b0d81e67bce
Unused code: binary_compose, identity

Seems noone is using those anymore.

Change-Id: I63f775d391c58753e89549dbcae8739708395487