Part of Nick Frisby's patch (c080f727)
for late demand-analysis removed the over-zealous short-cut whereby
strictness wrappers were not spelled out in detail in interface files.

This patch completes the process by
 * removing InlineWrapper from UnfoldingSource
 * removing IfWrapper from IfaceUnfolding

There was a tiny bit of special ad-hocery for wrappers, in OccurAnal,
but fortunately that too turns out to be rendered irrelevant by
the more uniform treatment, and after that there was no need
to remember which functions are wrappers.