为什么这个循环故意没有优化？

Question

https://github.com/ASP-NET-MVC/aspnetwebstack/blob/master/src/System.Web.Helpers/Crypto.cs#L159

// Compares two byte arrays for equality. The method is specifically written so that the loop is not optimized.
[MethodImpl(MethodImplOptions.NoOptimization)]
private static bool ByteArraysEqual(byte[] a, byte[] b)
{
    if (ReferenceEquals(a, b))
    {
        return true;
    }

    if (a == null || b == null || a.Length != b.Length)
    {
        return false;
    }

    bool areSame = true;
    for (int i = 0; i < a.Length; i++)
    {
        areSame &= (a[i] == b[i]);
    }
    return areSame;
}