Ensure that syntax tree actions are also re-executed by the solution crawler...

Ensure that syntax tree actions are also re-executed by the solution crawler when compilation options (or analyzer rule severities) are changed.

Fixes #3796

src/EditorFeatures/Test/SolutionCrawler/WorkCoordinatorTests.cs

@@ -205,7 +205,7 @@ public void Project_AssemblyName_Change()
                 var project = workspace.CurrentSolution.Projects.First(p => p.Name == "P1").WithAssemblyName("newName");
                 var worker = ExecuteOperation(workspace, w => w.ChangeProject(project.Id, project.Solution));
 
-                Assert.Equal(0, worker.SyntaxDocumentIds.Count);
+                Assert.Equal(5, worker.SyntaxDocumentIds.Count);
                 Assert.Equal(5, worker.DocumentIds.Count);
             }
         }
@@ -222,7 +222,7 @@ public void Project_AnalyzerOptions_Change()
                 var project = workspace.CurrentSolution.Projects.First(p => p.Name == "P1").AddAdditionalDocument("a1", SourceText.From("")).Project;
                 var worker = ExecuteOperation(workspace, w => w.ChangeProject(project.Id, project.Solution));
 
-                Assert.Equal(0, worker.SyntaxDocumentIds.Count);
+                Assert.Equal(5, worker.SyntaxDocumentIds.Count);
                 Assert.Equal(5, worker.DocumentIds.Count);
             }
         }

src/Features/Core/SolutionCrawler/InvocationReasons_Constants.cs

@@ -29,6 +29,7 @@ internal partial struct InvocationReasons
         public static readonly InvocationReasons ProjectConfigurationChanged =
             new InvocationReasons(
                 ImmutableHashSet.Create<string>(
+                                    PredefinedInvocationReasons.SyntaxChanged,
                                     PredefinedInvocationReasons.SemanticChanged));
 
         public static readonly InvocationReasons SolutionRemoved =