Dependency of attached bitcode targets to initial targets

[compor]

Dependency of attached bitcode targets to the initial targets should either be reverse or left entirely to the user, allowing for the creation of pass pipelines, etc.

[compor]

Resolved at release 2.0.2

The dependency relation of the attached targets is left to the user.

Moreover, examples are adapted to the above and they also provide a sort of "pipeline" dummy target for a group of passes.

Lastly, attached targets are by default excluded from the default build, but that can be easily added back using the appropriate property. This can be done only a few times with the use of the aforementioned dummy targets. This also aims to allow greater flexibility and user control.