Disable some library tests on ARMv6 architecture due to failures (#64733)

Related issues:

[mono][arm6][linux] System.Net.Ping.Functional.Tests failed #64673
[mono][arm6][linux] System.Net.Tests.ServicePointManagerTest.FindServicePoint_Collectible failed. #64674
[mono][arm6][linux] System.Reflection.Tests.ModuleTests.GetField failed #64675
Co-authored-by: NAdeel Mujahid <3840695+am11@users.noreply.github.com>

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

@@ -51,6 +51,7 @@ public static partial class PlatformDetection
         public static bool IsNotArm64Process => !IsArm64Process;
         public static bool IsArmOrArm64Process => IsArmProcess || IsArm64Process;
         public static bool IsNotArmNorArm64Process => !IsArmOrArm64Process;
+        public static bool IsArmv6Process => (int)RuntimeInformation.ProcessArchitecture == 7; // Architecture.Armv6
         public static bool IsX86Process => RuntimeInformation.ProcessArchitecture == Architecture.X86;
         public static bool IsNotX86Process => !IsX86Process;
         public static bool IsArgIteratorSupported => IsMonoRuntime || (IsWindows && IsNotArmProcess && !IsNativeAot);

src/libraries/System.Net.ServicePoint/tests/ServicePointManagerTest.cs

@@ -284,6 +284,7 @@ public static void FindServicePoint_ReturnsCachedServicePoint()
 
         [ConditionalFact(typeof(RemoteExecutor), nameof(RemoteExecutor.IsSupported))]
         [ActiveIssue("https://github.com/dotnet/runtime/issues/36217", typeof(PlatformDetection), nameof(PlatformDetection.IsMonoInterpreter))]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/64674", typeof(PlatformDetection), nameof(PlatformDetection.IsArmv6Process))]
         public static void FindServicePoint_Collectible()
         {
             RemoteExecutor.Invoke(() =>

src/libraries/System.Runtime/tests/System/Reflection/ModuleTests.cs

@@ -164,6 +164,7 @@ public void GetField_NullName()
 
         [Fact]
         [ActiveIssue("https://github.com/dotnet/runtime/issues/60558", TestPlatforms.Android)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/64675", typeof(PlatformDetection), nameof(PlatformDetection.IsArmv6Process))]
         public void GetField()
         {
             FieldInfo testInt = TestModule.GetField("TestInt", BindingFlags.Public | BindingFlags.Static);

src/libraries/tests.proj

@@ -47,6 +47,11 @@ Roslyn4.0.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Transactions.Local\tests\System.Transactions.Local.Tests.csproj" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetArchitecture)' == 'ARMv6'">
+    <!-- https://github.com/dotnet/runtime/issues/64673 -->
+    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Ping\tests\FunctionalTests\System.Net.Ping.Functional.Tests.csproj" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetsMobile)' == 'true' or '$(TargetArchitecture)' == 'ARMv6'">
     <!-- DllImportGenerator runtime tests depend on DNNE, which does not support mobile platforms. -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.InteropServices\tests\DllImportGenerator.Tests\DllImportGenerator.Tests.csproj" />