indy-based string-switch proposal

[John Rose]

On Nov 5, 2019, at 1:06 AM, Brian Goetz <brian.goetz at oracle.com> wrote:
> 
> Note that we want to use this technique for all switches except those over int and smaller.  

There are cases where smaller types should be handed to the library also.
I know this would be profitable for character classification switches (usable
by parsers!), which is why I called out that case at the end of my long message.
LLVM is having some fun with those; we should too.