Merge in 'release/5.0' changes

Author: dotnet-bot

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

@@ -40,6 +40,7 @@ public static partial class PlatformDetection
         public static bool IsNotArm64Process => !IsArm64Process;
         public static bool IsArmOrArm64Process => IsArmProcess || IsArm64Process;
         public static bool IsNotArmNorArm64Process => !IsArmOrArm64Process;
+        public static bool IsX86Process => RuntimeInformation.ProcessArchitecture == Architecture.X86;
         public static bool IsArgIteratorSupported => IsMonoRuntime || (IsWindows && IsNotArmProcess);
         public static bool IsArgIteratorNotSupported => !IsArgIteratorSupported;
         public static bool Is32BitProcess => IntPtr.Size == 4;

src/libraries/System.Globalization/tests/IcuTests.cs

@@ -10,7 +10,9 @@ namespace System.Globalization.Tests
     public class IcuTests
     {
         private static bool IsIcuCompatiblePlatform => PlatformDetection.IsNotWindows ||
-                                                       PlatformDetection.IsWindows10Version1903OrGreater;
+                                                       PlatformDetection.IsWindows10Version1903OrGreater &&
+                                                        // Server core doesn't have icu.dll on SysWOW64
+                                                        !(PlatformDetection.IsWindowsServerCore && PlatformDetection.IsX86Process);
 
         [ConditionalFact(nameof(IsIcuCompatiblePlatform))]
         public static void IcuShouldBeUsedByDefault()