Merge pull request #13008 from heejaechang/objectPRfeedback

address Chuck's PR feedback

src/Compilers/Core/CodeAnalysisTest/Collections/BitArrayTests.cs

@@ -163,6 +163,8 @@ public void CheckWords()
 
                 var required = BitVector.WordsRequired(capacity);
                 var count = BitVector.AllSet(capacity).Words().Count();
+
+                Assert.Equal(required, count);
             }
         }
 

src/Compilers/Core/Portable/Serialization/ObjectReader.cs

@@ -411,7 +411,7 @@ private Array ReadPrimitiveTypeArrayElements(Type type, DataKind kind, int lengt
             }
         }
 
-        private Array ReadBooleanArray(int length)
+        private bool[] ReadBooleanArray(int length)
         {
             if (length == 0)
             {
@@ -441,7 +441,7 @@ private Array ReadBooleanArray(int length)
             return array;
         }
 
-        private T[] ReadPrimitiveTypeArrayElements<T>(int length, Func<T> read)
+        private static T[] ReadPrimitiveTypeArrayElements<T>(int length, Func<T> read)
         {
             if (length == 0)
             {

src/Compilers/Core/Portable/Serialization/ObjectWriter.cs

@@ -579,7 +579,7 @@ private void WriteBooleanArray(bool[] array)
             }
         }
 
-        private void WritePrimitiveTypeArrayElements<T>(T[] array, Action<T> write)
+        private static void WritePrimitiveTypeArrayElements<T>(T[] array, Action<T> write)
         {
             for (var i = 0; i < array.Length; i++)
             {