On default runtime binary size

[dcodeIO]

As of #717 it seems that bundling the full runtime by default leads to confusion regarding binary file size. That's one thing I've been worried about when the runtime landed.

The underlying reason is that the full runtime exposes the runtime interfaces externally, so the loader can pick these up, and whatever is reached from the runtime exports becomes compiled. The alternative is to use the half runtime by default, which can properly DCE if none of its functionality is used, but will then lead to issues being opened asking why the loader isn't working as expected I guess.

Any ideas?

[MaxGraey]

What about scan all exported functions and classes. If we have unmanaged types in arguments and return value like i32, bool, f64 we don't need full runtime and use half runtime as default.

[dcodeIO]

Closing this issue as part of 2020 vacuum because it cannot really be fixed. Also, there have been other improvements on this front meanwhile, like stripping cyclic garbage collection logic if it isn't needed.