Remove relics of regex swash use

Remove relics of regex swash use

This removes the most obvious and easy things that are no longer needed
since regexes no longer use swashes at all.

tr/// continues, for the time being, to use swashes, so not all swash
handling is removable now.  But tr/// doesn't use inversion lists, and
so a bunch of code is ripped out here.  Other code could have been, but
I did only the relatively easy stuff.  The rest can be ripped out all at
once when tr/// is stops using swashes.