List available targets

[Arik]

I'm trying in vain to run cargo instruments --bench <name> inside a workspace containing multiple members, each with multiple test and bench targets. Unfortunately, the only error I ever get is

Failed missing target bench <name>

I cannot find a single example of how to specify a given bench target, or really any target that isn't just the main.rs file, nor does there appear to be a way to get the list of available targets.

Given that to throw the error, the app first collects a list of all available targets here, it would be extremely helpful to have the ability to just print that particular list.

[Colin Rofls]

This does sound useful, and I would be happy to accept a patch for it; otherwise I'll take a look next time I'm making substantive changes. :)