tweak how we merge build and live errors for language such as F#

src/Features/Core/Portable/Diagnostics/EngineV2/DiagnosticIncrementalAnalyzer.StateManager.cs

@@ -122,6 +122,14 @@ public StateSet GetOrCreateStateSet(Project project, DiagnosticAnalyzer analyzer
             /// </summary>
             public ImmutableArray<StateSet> CreateBuildOnlyProjectStateSet(Project project)
             {
+                if (!project.SupportsCompilation)
+                {
+                    // languages which don't use our compilation model but diagnostic framework,
+                    // all their analyzer should be host analyzers. return all host analyzers
+                    // for the language
+                    return _hostStates.GetOrCreateStateSets(project.Language).ToImmutableArray();
+                }
+
                 // create project analyzer reference identity map
                 var referenceIdentities = project.AnalyzerReferences.Select(r => _analyzerManager.GetAnalyzerReferenceIdentity(r)).ToSet();