How to handle the test folder

[davidanthoff]

Maybe more an issue for LS actually, but I think in general we need to come up with a plan what we do about the test folder.

I think fundamentally we should think of the code in the test folder as running in a different environment than the rest of the code, namely in a synthetic environment that is the union of the normal + test environment. Maybe the way to handle this is in the LS have two symbol stores, one for the "normal" code, one for the "test" folder. Then also have two instances of symbol server, And have them just return a symbol store for both.

The env for the test folder doesn't really exist on disc, so we'll have to create that from a merge from the default and test stuff. I think we might be able to reuse the code from the test runner in Pkg.jl for that.

I'd say we can solve this whole problem once we have the load times under control, i.e. next version :)