Apple Silicon platform detection (#49155)

* Add Apple Silicon PlatformDetection

* Disable OSVersion_ValidVersion_OSX on Apple Silicon

* Update docs

docs/workflow/testing/libraries/filtering-tests.md

@@ -62,6 +62,10 @@ This attribute returns the 'failing' category, which is disabled by default.
 ```cs
 [ActiveIssue(string issue, TestPlatforms platforms, TargetFrameworkMonikers frameworks)]
 ```
+**Disable using PlatformDetection filter:**
+```cs
+[ActiveIssue(string issue, typeof(PlatformDetection), nameof(PlatformDetection.{member name}))]
+```
 Use this attribute over test methods to skip failing tests only on the specific platforms and the specific target frameworks.
 
 #### SkipOnTargetFrameworkAttribute

src/libraries/Common/tests/TestUtilities/System/PlatformDetection.Unix.cs

@@ -40,6 +40,8 @@ public static partial class PlatformDetection
         public static bool IsNotOSX => !IsOSX;
         public static bool IsMacOsMojaveOrHigher => IsOSX && Environment.OSVersion.Version >= new Version(10, 14);
         public static bool IsMacOsCatalinaOrHigher => IsOSX && Environment.OSVersion.Version >= new Version(10, 15);
+        public static bool IsMacOsAppleSilicon => IsOSX && IsArm64Process;
+        public static bool IsNotMacOsAppleSilicon => !IsMacOsAppleSilicon;
 
         // RedHat family covers RedHat and CentOS
         public static bool IsRedHatFamily => IsRedHatFamilyAndVersion();

src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs

@@ -183,6 +183,7 @@ public void OSVersion_ParseVersion(string input, int major, int minor, int build
 
         [Fact]
         [PlatformSpecific(TestPlatforms.OSX)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/49106", typeof(PlatformDetection), nameof(PlatformDetection.IsNotMacOsAppleSilicon))]
         public void OSVersion_ValidVersion_OSX()
         {
             Version version = Environment.OSVersion.Version;