Change CodeLengthCodeOrder, LiteralMap and Norm to ReadOnlySpan

src/ImageSharp/Formats/Webp/Lossless/WebpLosslessDecoder.cs

@@ -65,15 +65,8 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
             FixedTableSize + 2704
         };
 
-        private static readonly byte[] CodeLengthCodeOrder = { 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
-
         private static readonly int NumCodeLengthCodes = CodeLengthCodeOrder.Length;
 
-        private static readonly byte[] LiteralMap =
-        {
-            0, 1, 1, 1, 0
-        };
-
         /// <summary>
         /// Initializes a new instance of the <see cref="WebpLosslessDecoder"/> class.
         /// </summary>
@@ -87,6 +80,12 @@ namespace SixLabors.ImageSharp.Formats.Webp.Lossless
             this.configuration = configuration;
         }
 
+        // This uses C#'s compiler optimization to refer to assembly's static data directly.
+        private static ReadOnlySpan<byte> CodeLengthCodeOrder => new byte[] { 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
+
+        // This uses C#'s compiler optimization to refer to assembly's static data directly.
+        private static ReadOnlySpan<byte> LiteralMap => new byte[] { 0, 1, 1, 1, 0 };
+
         /// <summary>
         /// Decodes the image from the stream using the bitreader.
         /// </summary>

src/ImageSharp/Formats/Webp/WebpLookupTables.cs

@@ -239,7 +239,8 @@ namespace SixLabors.ImageSharp.Formats.Webp
             }
         };
 
-        public static readonly byte[] Norm =
+        // This uses C#'s compiler optimization to refer to assembly's static data directly.
+        public static ReadOnlySpan<byte> Norm => new byte[]
         {
             // renorm_sizes[i] = 8 - log2(i)
             7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,