Function run 

pub fn run(placed: &Placed, backend: Arc<dyn Backend>, opts: &Options) -> Report

Run every test and property block in a compiled program.

On a thread with as much host stack as the backend says it needs ([Backend::stack_bytes]), because a test is the most likely place for a program to recurse further than its author expected and the answer to that has to be a failing case rather than a dead process. A backend that needs nothing gets no thread.