Justification for Compiler and Linker Features

# Scope

I'd like to kick off a thread discussing the [Compiler and Linker Features](https://cps-org.github.io/cps/features.html#linker-features) section of the specification, mostly because I'm not sure what to do with it.

I'd like to hear the motivating use cases for these features. There are other alternatives to approaching those outcomes, including not worrying about relevant use cases yet, and I'd like to make sure I understand why this approach was used.

Note that most modern build and packaging systems have some notion of "profiles" or "toolchain specifications" that sort of serve the same purpose. I was expecting the ecosystem would want to converge on some commonalities in those problems, but I was expecting we could circle back to that later, or perhaps even in a different specification.

# Completion Criteria

Any of these should be fine:

* Developer documentation to clarify the motivation for the use cases, perhaps just linking to this discussion from wiki pages if nothing else
* A new enhancement issue to circle back on this later
* ...and a pull request to remove the Compiler and Linker Features page, at least temporarily