Re-enable some analyzer tests (#1550)

* Re-enable tests that were disabled for #1364

* Initial plan

* Add SkipLocalDiagnosticCheck to transitive code fix tests

The VSTHRD010 analyzer reports transitive diagnostics via
RegisterCompilationEndAction, which the Roslyn testing framework
classifies as 'non-local'. The test framework throws
'Code fix is attempting to provide a fix for a non-local analyzer
diagnostic' unless CodeFixTestBehaviors.SkipLocalDiagnosticCheck
is set. This adds that flag to the three affected test instances.

Co-authored-by: AArnott <3548+AArnott@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: AArnott <3548+AArnott@users.noreply.github.com>

Author: AArnott

test/Microsoft.VisualStudio.Threading.Analyzers.Tests/VSTHRD010MainThreadUsageAnalyzerTests.cs

@@ -215,7 +215,7 @@ class Test {
         }.RunAsync();
     }
 
-    [Fact(Skip = "Started failing after CodeAnalysis upgrade that caught a bug in the code fix. #1364")]
+    [Fact]
     public async Task TransitiveNoCheck_InCtor()
     {
         var test = @"
@@ -285,6 +285,10 @@ static void VerifyOnUIThread() {
             ExpectedDiagnostics = { expected },
             FixedCode = fix1,
             CodeActionIndex = CodeFixIndex.VerifyOnUIThread,
+
+            // SkipLocalDiagnosticCheck is required because this diagnostic is reported at compilation-end
+            // (as a transitive/indirect diagnostic), not as a local one. See https://github.com/microsoft/vs-threading/issues/1364.
+            CodeFixTestBehaviors = CodeFixTestBehaviors.SkipLocalDiagnosticCheck,
         }.RunAsync();
 
         await new CSVerify.Test
@@ -293,6 +297,10 @@ static void VerifyOnUIThread() {
             ExpectedDiagnostics = { expected },
             FixedCode = fix2,
             CodeActionIndex = CodeFixIndex.ThrowIfNotOnUIThreadIndex1,
+
+            // SkipLocalDiagnosticCheck is required because this diagnostic is reported at compilation-end
+            // (as a transitive/indirect diagnostic), not as a local one. See https://github.com/microsoft/vs-threading/issues/1364.
+            CodeFixTestBehaviors = CodeFixTestBehaviors.SkipLocalDiagnosticCheck,
         }.RunAsync();
     }
 
@@ -522,7 +530,7 @@ void VerifyOnUIThread() {
         await CSVerify.VerifyAnalyzerAsync(test, expected);
     }
 
-    [Fact(Skip = "Started failing after CodeAnalysis upgrade that caught a bug in the code fix. #1364")]
+    [Fact]
     public async Task RequiresUIThreadTransitive_MultipleInMember()
     {
         var test = @"
@@ -587,6 +595,10 @@ static void VerifyOnUIThread() { }
             },
             FixedCode = fix,
             CodeActionIndex = CodeFixIndex.VerifyOnUIThread,
+
+            // SkipLocalDiagnosticCheck is required because this diagnostic is reported at compilation-end
+            // (as a transitive/indirect diagnostic), not as a local one. See https://github.com/microsoft/vs-threading/issues/1364.
+            CodeFixTestBehaviors = CodeFixTestBehaviors.SkipLocalDiagnosticCheck,
         }.RunAsync();
     }