Replace PVS dictionaries with memory magic (#4795)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Robust.Shared.Maths/MathHelper.cs

@@ -697,6 +697,32 @@ namespace Robust.Shared.Maths
 
         #endregion
 
+        /// <summary>
+        /// Round up (ceiling) a value to a multiple of a known power of two.
+        /// </summary>
+        /// <param name="value">The value to round up.</param>
+        /// <param name="powerOfTwo">
+        /// The power of two to round up to a multiple of. The result is undefined if this is not a power of two.
+        /// </param>
+        /// <remarks>
+        /// The result is undefined if either value is negative.
+        /// </remarks>
+        /// <typeparam name="T">The type of integer to operate on.</typeparam>
+        /// <example>
+        /// <code>
+        /// MathHelper.CeilMultiplyPowerOfTwo(5, 4) // 8
+        /// MathHelper.CeilMultiplyPowerOfTwo(4, 4) // 4
+        /// MathHelper.CeilMultiplyPowerOfTwo(8, 4) // 8
+        /// </code>
+        /// </example>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T CeilMultipleOfPowerOfTwo<T>(T value, T powerOfTwo) where T : IBinaryInteger<T>
+        {
+            var mask = powerOfTwo - T.One;
+            var remainder = value & mask;
+            return remainder == T.Zero ? value : (value | mask) + T.One;
+        }
+
         #endregion Public Members
     }
 }