Add adler tests with and without intrinsics

tests/ImageSharp.Tests/Formats/Png/Adler32Tests.cs

@@ -3,6 +3,7 @@
 
 using System;
 using SixLabors.ImageSharp.Compression.Zlib;
+using SixLabors.ImageSharp.Tests.TestUtilities;
 using Xunit;
 using SharpAdler32 = ICSharpCode.SharpZipLib.Checksum.Adler32;
 
@@ -15,10 +16,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
         [InlineData(0)]
         [InlineData(1)]
         [InlineData(2)]
-        public void ReturnsCorrectWhenEmpty(uint input)
-        {
-            Assert.Equal(input, Adler32.Calculate(input, default));
-        }
+        public void CalculateAdler_ReturnsCorrectWhenEmpty(uint input) => Assert.Equal(input, Adler32.Calculate(input, default));
 
         [Theory]
         [InlineData(0)]
@@ -28,24 +26,46 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
         [InlineData(1024 + 15)]
         [InlineData(2034)]
         [InlineData(4096)]
-        public void MatchesReference(int length)
+        public void CalculateAdler_MatchesReference(int length) => CalculateAdlerAndCompareToReference(length);
+
+        private static void CalculateAdlerAndCompareToReference(int length)
         {
-            var data = GetBuffer(length);
+            // arrange
+            byte[] data = GetBuffer(length);
             var adler = new SharpAdler32();
             adler.Update(data);
-
             long expected = adler.Value;
+
+            // act
             long actual = Adler32.Calculate(data);
 
+            // assert
             Assert.Equal(expected, actual);
         }
 
         private static byte[] GetBuffer(int length)
         {
-            var data = new byte[length];
+            byte[] data = new byte[length];
             new Random(1).NextBytes(data);
 
             return data;
         }
+
+#if SUPPORTS_RUNTIME_INTRINSICS
+        [Fact]
+        public void RunCalculateAdlerTest_WithHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunCalculateAdlerTest, HwIntrinsics.AllowAll);
+
+        [Fact]
+        public void RunCalculateAdlerTest_WithoutHardwareIntrinsics_Works() => FeatureTestRunner.RunWithHwIntrinsicsFeature(RunCalculateAdlerTest, HwIntrinsics.DisableHWIntrinsic);
+
+        private static void RunCalculateAdlerTest()
+        {
+            int[] testData = { 0, 8, 215, 1024, 1024 + 15, 2034, 4096 };
+            for (int i = 0; i < testData.Length; i++)
+            {
+                CalculateAdlerAndCompareToReference(testData[i]);
+            }
+        }
+#endif
     }
 }