This plugin provides a concise command that uses B::Concise to dump
optrees of expressions.
The code is not actually executed, which means that when used with
Deve::REPL::Plugin::OutputCache there is no new value in _.
The command takes the same options as compile in B::Concise, e.g. -basic or
-exec to determine the dump order, -debug, -concise and -terse to
determine the formatting, etc.