Remove RuntimeMemory.GetArrayElements()

This method copied every element in the array to a new array, so it increases memory consumption. Besides, it doesn't include values in the dictionary. 

This pull request remove this method and replace with ArrayUtils.GetValues() which is refactored as well to return  ``IEnumerable<StackValue>`` as in most cases we just iterate through elements.
You can change the return type of this to IEnumerable<T>