Add test for parameterless ctor dotnet#45119

Calling `ActivatorUtilities.CreateInstance` without additional arguments
should prefer parameterless constructor as there are no guarantees that
parameters, for which arguments were not supplied, can be resolved from
the ServiceProvider.

src/libraries/Microsoft.Extensions.DependencyInjection.Specification.Tests/src/ActivatorUtilitiesTests.cs

@@ -250,6 +250,22 @@ public void TypeActivatorCreateInstanceUsesMarkedConstructor(int argument1, stri
             Assert.Equal(ctor, ((ClassWithAmbiguousCtorsAndAttributeFirst)instance).CtorUsed);
         }
 
+        [Fact]
+        public void TypeActivatorCreateInstanceUsesParameterlessConstructor()
+        {
+            // Arrange
+            var serviceCollection = new TestServiceCollection();
+            serviceCollection.AddSingleton<IFakeService, FakeService>();
+            var serviceProvider = CreateServiceProvider(serviceCollection);
+            var type = typeof(ClassWithParameterlessCtor);
+
+            // Act
+            var instance = ActivatorUtilities.CreateInstance(serviceProvider, type);
+
+            // Assert
+            Assert.Equal("Parameterless", ((ClassWithParameterlessCtor)instance).CtorUsed);
+        }
+
         [Theory]
         [MemberData(nameof(CreateInstanceFuncs))]
         public void TypeActivatorUsesMarkedConstructor(CreateInstanceFunc createFunc)

src/libraries/Microsoft.Extensions.DependencyInjection.Specification.Tests/src/Fakes/ClassWithParameterlessCtor.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.Extensions.DependencyInjection.Specification.Fakes
+{
+    public class ClassWithParameterlessCtor
+    {
+        public ClassWithParameterlessCtor(IFakeService dependency)
+        {
+            CtorUsed = "IFakeService";
+        }
+
+        public ClassWithParameterlessCtor()
+        {
+            CtorUsed = "Parameterless";
+        }
+
+        public string CtorUsed { get; set; }
+    }
+}