Specify TaskCreationOptions when using TCS

Fixes #8558

Author: pranavkm

src/Microsoft.AspNetCore.Mvc.Razor/Internal/RazorViewCompiler.cs

@@ -181,7 +181,7 @@ private Task<CompiledViewDescriptor> OnCacheMiss(string normalizedPath)
                     cacheEntryOptions.ExpirationTokens.Add(item.ExpirationTokens[i]);
                 }
 
-                taskSource = new TaskCompletionSource<CompiledViewDescriptor>();
+                taskSource = new TaskCompletionSource<CompiledViewDescriptor>(creationOptions: TaskCreationOptions.RunContinuationsAsynchronously);
                 if (item.SupportsCompilation)
                 {
                     // We'll compile in just a sec, be patient.

src/Microsoft.AspNetCore.Mvc.TagHelpers/Cache/DistributedCacheTagHelperService.cs

@@ -88,7 +88,7 @@ public async Task<IHtmlContent> ProcessContentAsync(TagHelperOutput output, Cach
                     // There is a small race condition here between TryGetValue and TryAdd that might cause the
                     // content to be computed more than once. We don't care about this race as the probability of
                     // happening is very small and the impact is not critical.
-                    var tcs = new TaskCompletionSource<IHtmlContent>();
+                    var tcs = new TaskCompletionSource<IHtmlContent>(creationOptions: TaskCreationOptions.RunContinuationsAsynchronously);
 
                     _workers.TryAdd(key, tcs.Task);
 

src/Microsoft.AspNetCore.Mvc.TagHelpers/CacheTagHelper.cs

@@ -108,7 +108,7 @@ private async Task<IHtmlContent> CreateCacheEntry(CacheTagKey cacheKey, TagHelpe
             var options = GetMemoryCacheEntryOptions();
             options.AddExpirationToken(new CancellationChangeToken(tokenSource.Token));
             options.SetSize(PlaceholderSize);
-            var tcs = new TaskCompletionSource<IHtmlContent>();
+            var tcs = new TaskCompletionSource<IHtmlContent>(creationOptions: TaskCreationOptions.RunContinuationsAsynchronously);
 
             // The returned value is ignored, we only do this so that
             // the compiler doesn't complain about the returned task