Code refactoring to remove duplicate API

Author: Sergio0694

Microsoft.Toolkit.HighPerformance/Buffers/StringPool.cs

@@ -5,15 +5,13 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Contracts;
-#if NETCOREAPP3_1
-using System.Numerics;
-#endif
 using System.Runtime.CompilerServices;
 using System.Text;
 using Microsoft.Toolkit.HighPerformance.Extensions;
 #if !NETSTANDARD1_4
 using Microsoft.Toolkit.HighPerformance.Helpers;
 #endif
+using BitOperations = Microsoft.Toolkit.HighPerformance.Helpers.Internals.BitOperations;
 
 #nullable enable
 
@@ -79,8 +77,8 @@ static void FindFactors(int size, int factor, out int x, out int y)
                     a = Math.Sqrt((double)size / factor),
                     b = factor * a;
 
-                x = RoundUpPowerOfTwo((int)a);
-                y = RoundUpPowerOfTwo((int)b);
+                x = BitOperations.RoundUpPowerOfTwo((int)a);
+                y = BitOperations.RoundUpPowerOfTwo((int)b);
             }
 
             // We want to find two powers of 2 factors that produce a number
@@ -130,30 +128,6 @@ static void FindFactors(int size, int factor, out int x, out int y)
             Size = p2;
         }
 
-        /// <summary>
-        /// Rounds up an <see cref="int"/> value to a power of 2.
-        /// </summary>
-        /// <param name="x">The input value to round up.</param>
-        /// <returns>The smallest power of two greater than or equal to <paramref name="x"/>.</returns>
-        [Pure]
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static int RoundUpPowerOfTwo(int x)
-        {
-#if NETCOREAPP3_1
-            return 1 << (32 - BitOperations.LeadingZeroCount((uint)(x - 1)));
-#else
-            x--;
-            x |= x >> 1;
-            x |= x >> 2;
-            x |= x >> 4;
-            x |= x >> 8;
-            x |= x >> 16;
-            x++;
-
-            return x;
-#endif
-        }
-
         /// <summary>
         /// Gets the shared <see cref="StringPool"/> instance.
         /// </summary>