Add polyfill for Random.Shared

PolyShim.Tests/Net60/RandomTests.cs

@@ -0,0 +1,18 @@
+using System;
+using FluentAssertions;
+using Xunit;
+
+namespace PolyShim.Tests.Net60;
+
+public class RandomTests
+{
+    [Fact]
+    public void Shared_Test()
+    {
+        // Act
+        var value = Random.Shared.Next(1, 100);
+
+        // Assert
+        value.Should().BeInRange(1, 100);
+    }
+}

PolyShim/Net60/Random.cs

@@ -0,0 +1,24 @@
+// The following comment is required to instruct analyzers to skip this file
+// <auto-generated/>
+
+#if (NETCOREAPP && !NET6_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+// ReSharper disable RedundantUsingDirective
+// ReSharper disable CheckNamespace
+// ReSharper disable InconsistentNaming
+// ReSharper disable PartialTypeWithSinglePart
+
+using System;
+
+internal static partial class PolyfillExtensions
+{
+    [ThreadStatic]
+    private static Random? _threadRandom;
+
+    extension(Random)
+    {
+        // https://learn.microsoft.com/dotnet/api/system.random.shared
+        public static Random Shared => _threadRandom ??= new Random();
+    }
+}
+#endif