fixes after rebase for 8.0

src/libraries/System.Collections.Concurrent/src/System/Collections/Concurrent/ConcurrentDictionary/DictionaryImpl`3.cs

@@ -764,7 +764,7 @@ namespace System.Collections.Concurrent
 
             // prev value is null or dead.
             // let's try install new value
-            newValObj = newValObj ?? ToObjectValue(result = valueFactory(key));
+            newValObj ??= ToObjectValue(result = valueFactory(key));
             while (true)
             {
                 Debug.Assert(!(entryValue is Prime));

src/libraries/System.Collections.Concurrent/tests/ConcurrentDictionary/ConcurrentDictionary.Generic.Tests.cs

@@ -44,6 +44,7 @@ namespace System.Collections.Concurrent.Tests
 
         protected override string CreateTValue(int seed) => CreateTKey(seed);
 
+        [ActiveIssue("Satori: tests implementation details")]
         [Theory]
         [InlineData(false)]
         [InlineData(true)]