Add source generator to VSIX

[tmat]

Adds source generator and its dependencies to VSIX.

Roslyn change: dotnet/roslyn#63912

[tmat]

Need someone to hit the button, can't merge myself. Thanks!

[davidwengier]

Is VS Mac on your radar anywhere? On this side it should be easy enough to add the files to the mpack, but I've no idea how the other side works. The code is probably in the vsmac repo, not Roslyn, I would expect.

[tmat]

@davidwengier Good point. Roslyn's code that loads analyzers from VSIX certainly does not work from VS Mac. Not sure if there is an equivalent code in VS Mac.

[davidwengier]

Correct me if I'm wrong @chsienki, but I don't think VS Mac is blocking. Obviously the SDK is still going to get updates from this repo, so until there is some break in the compiler/tooling that means tooling no longer works with the SDK compiler, it's probably fine for VS Mac to lag a little. Plus I suspect such a break is undesirable for lots of other reasons. And besides that, the LSP editor is still behind a feature flag.

[jaredpar]

it's probably fine for VS Mac to lag a little.

I agree it's fine to lag a little but would like to know what the plan is there.

[chsienki]

Yeah, in the immediate/short term this doesn't affect VSMac or VSCode, they'll keep loading it from the SDK. In the near future we're going to want to do the same thing for them as well though. I'm working on figuring out the overall architecture which should give us a good idea of how we want to achieve that. I'll open a couple of issues to track that specific work though so we don't forget about it:

• VSMac should prefer MPack'ed generator over SDK
• VSCode should prefer extension generator over SDK