Add polyfill for Type.IsAssignableTo

Meziantou.Polyfill.Editor/M;System.Type.IsAssignableTo(System.Type).cs

@@ -0,0 +1,10 @@
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+static partial class PolyfillExtensions
+{
+    public static bool IsAssignableTo(this Type target, [NotNullWhen(true)] Type? targetType)
+    {
+        return targetType?.IsAssignableFrom(target) ?? false;
+    }
+}

Meziantou.Polyfill.Tests/UnitTest1.cs

@@ -754,6 +754,14 @@ public void Enumerable_Index()
     {
         Assert.Equal([(0, "a"), (1, "b")], (new string[] { "a", "b" }).Index());
     }
+
+    [Fact]
+    public void Type_IsAssignableTo()
+    {
+        Assert.True(typeof(string).IsAssignableTo(typeof(object)));
+        Assert.True(typeof(string).IsAssignableTo(typeof(string)));
+        Assert.False(typeof(string).IsAssignableTo(typeof(int)));
+    }
 
     [Fact]
     public void CollectionBuilder()

Meziantou.Polyfill/Meziantou.Polyfill.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
-    <Version>1.0.36</Version>
+    <Version>1.0.37</Version>
     <TransformOnBuild>true</TransformOnBuild>
 
     <LangVersion>preview</LangVersion>

README.md

@@ -201,6 +201,7 @@ By default, all needed polyfills are generated. You can configure which polyfill
 - `System.Text.StringBuilder.Replace(System.ReadOnlySpan<System.Char> oldValue, System.ReadOnlySpan<System.Char> newValue, System.Int32 startIndex, System.Int32 count)`
 - `System.Threading.CancellationTokenSource.CancelAsync()`
 - `System.Threading.Tasks.Task.WaitAsync(System.Threading.CancellationToken cancellationToken)`
+- `System.Type.IsAssignableTo(System.Type? targetType)`
 
 <!-- end_polyfills -->