Allow combination of NOINLINE and INLINEABLE.
Allow combination of NOINLINE/INLINEABLE.
We do this by also tracking INLINEABLE outside of the Unfolding data
type as it's own flag.
In the proccess of this I made a few other smaller changes.
* Allow NOINLINE bindings to specialise with -fspecialise-aggressively.
Fixes #21036
* Made rule source a proper type instead of Bool.