Roslyn: EnC: Avoid checking for semantic errors on the entire compilation

[tmat]

It's expensive, can we avoid it?

http://source.roslyn.io/#Microsoft.CodeAnalysis.Features/EditAndContinue/AbstractEditAndContinueAnalyzer.cs,441

[gavinhuet]

This issue is making EnC unusable in our application.
It can take 20s to over a minute to make the simplest of changes i.e. not logic, just changing a string value.
Stopping debugging and rebuilding the app is quicker!

[ManishJayaswal]

Another customer is seeing perf issues during debugging because of this. We should see if we can prioratize this and get it fixed for RTM.

[gavinhuet]

What is the status of this issue? Would love to have it resolved sooner rather than later.

[tmat]

Fixed by https://github.com/dotnet/roslyn/pull/19167.