Always do the worker/wrapper split for NOINLINEs
Trac #10069 (closed) revealed that small NOINLINE functions didn't get split
into worker and wrapper. This was due to certainlyWillInline
saying that any unfoldings with a guidance of UnfWhen
inline
unconditionally. That isn't the case for NOINLINE functions, so we
catch this case earlier now.
Edited by Sebastian Graf