Allow AsLPArray test to succeed without COM (#74552)

src/tests/Common/CoreCLRTestLibrary/PlatformDetection.cs

@@ -13,5 +13,12 @@ public static class PlatformDetection
     
         public static bool IsX86Process => RuntimeInformation.ProcessArchitecture == Architecture.X86;
         public static bool IsNotX86Process => !IsX86Process;
+
+        public static bool IsWindows => OperatingSystem.IsWindows();
+
+        public static bool IsBuiltInComEnabled => IsWindows
+                                            && (AppContext.TryGetSwitch("System.Runtime.InteropServices.BuiltInComInterop.IsSupported", out bool isEnabled)
+                                                ? isEnabled
+                                                : true);
     }
 }

src/tests/Interop/PInvoke/Array/MarshalArrayAsParam/AsLPArray/AsLPArrayTest.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Runtime.InteropServices;
+using TestLibrary;
 using Xunit;
 
 public class ArrayMarshal
@@ -316,7 +317,7 @@ private static void TestMarshalByVal_NoAttributes()
         Assert.True(CStyle_Array_Struct(InitStructArray(ARRAY_SIZE), ARRAY_SIZE));
         Assert.True(CStyle_Array_Bool(InitBoolArray(ARRAY_SIZE), ARRAY_SIZE));
 
-        if (OperatingSystem.IsWindows())
+        if (PlatformDetection.IsBuiltInComEnabled)
         {
             object[] oArr = InitArray<object>(ARRAY_SIZE);
             // Test nesting null value scenario
@@ -349,7 +350,7 @@ private static void TestMarshalByVal_In()
         Assert.True(CStyle_Array_Struct_In(InitStructArray(ARRAY_SIZE), ARRAY_SIZE));
         Assert.True(CStyle_Array_Bool_In(InitBoolArray(ARRAY_SIZE), ARRAY_SIZE));
 
-        if (OperatingSystem.IsWindows())
+        if (PlatformDetection.IsBuiltInComEnabled)
         {
             object[] oArr = InitArray<object>(ARRAY_SIZE);
             // Test nesting null value scenario
@@ -556,7 +557,7 @@ private static void TestMarshalByVal_Out()
         Assert.True(CStyle_Array_Bool_Out(boolArr, ARRAY_SIZE));
         Assert.True(Equals<bool>(boolArr, GetExpectedOutBoolArray(ARRAY_SIZE)));
 
-        if (OperatingSystem.IsWindows())
+        if (PlatformDetection.IsBuiltInComEnabled)
         {
             object[] oArr = new object[ARRAY_SIZE];
             Assert.True(CStyle_Array_Object_Out(oArr, ARRAY_SIZE));