If a literal is entirely whitespace, then it's quite likely that it is
very common. So when that case occurs, just don't do (inner) literal
optimizations at all.
The regex engine may still make sub-optimal decisions here, but that's a
problem for another day.
Fixes#1087
The top-level listing was just getting a bit too long for my taste. So
put all of the code in one directory and shrink the large top-level mess
to a small top-level mess.
NOTE: This commit only contains renames. The subsequent commit will
actually make ripgrep build again. We do it this way with the naive hope
that this will make it easier for git history to track the renames.
Sigh.
