Add RequiresLocationAttribute polyfill

PolySharp.sln

@@ -6,7 +6,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PolySharp.SourceGenerators"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Projects", "Projects", "{8DAA0C71-4529-44EB-8994-DE331A3ADC52}"
 	ProjectSection(SolutionItems) = preProject
+		src\PolySharp.Package\icon.png = src\PolySharp.Package\icon.png
 		src\PolySharp.Package\PolySharp.Package.msbuildproj = src\PolySharp.Package\PolySharp.Package.msbuildproj
+		src\PolySharp.Package\README.md = src\PolySharp.Package\README.md
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tests", "Tests", "{D65D0307-1D0F-499D-945B-E33E71F251A4}"
@@ -37,7 +39,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PolySharp.MinimumCSharpVers
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PolySharp.PolySharpUseTypeAliasForUnmanagedCallersOnlyAttribute.Tests", "tests\PolySharp.PolySharpUseTypeAliasForUnmanagedCallersOnlyAttribute.Tests\PolySharp.PolySharpUseTypeAliasForUnmanagedCallersOnlyAttribute.Tests.csproj", "{C865CEDE-2DC9-4E1E-BB58-529E6E2A9DBB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PolySharp.TypeForwards.Tests", "tests\PolySharp.TypeForwards.Tests\PolySharp.TypeForwards.Tests.csproj", "{AAF3B574-66F1-4EF0-936A-82390E30D539}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PolySharp.TypeForwards.Tests", "tests\PolySharp.TypeForwards.Tests\PolySharp.TypeForwards.Tests.csproj", "{AAF3B574-66F1-4EF0-936A-82390E30D539}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

README.md

@@ -49,6 +49,7 @@ Here's an example of some of the new features that **PolySharp** can enable down
 - `[AsyncMethodBuilder]` (needed for [custom method builder types](https://learn.microsoft.com/dotnet/csharp/language-reference/proposals/csharp-10.0/async-method-builders))
 - `[StringSyntax]` (needed to enable [syntax highlight in the IDE](https://github.com/dotnet/runtime/issues/62505))
 - `[ModuleInitializer]` (needed to enable [custom module initializers](https://learn.microsoft.com/dotnet/csharp/language-reference/proposals/csharp-9.0/module-initializers))
+- `[RequiresLocation]` (needed to enable [ref readonly parameters](https://github.com/dotnet/csharplang/issues/6010))
 
 To leverage them, make sure to bump your C# language version. You can do this by setting the `<LangVersion>` MSBuild property in your project. For instance, by adding `<LangVersion>11.0</LangVersion>` (or your desired C# version) to the first `<PropertyGroup>` of your .csproj file. For more info on this, [see here](https://sergiopedri.medium.com/enabling-and-using-c-9-features-on-older-and-unsupported-runtimes-ce384d8debb), but remember that you don't need to manually copy polyfills anymore: simply adding a reference to **PolySharp** will do this for you automatically.
 

src/PolySharp.Package/README.md

@@ -47,6 +47,7 @@ Here's an example of some of the new features that **PolySharp** can enable down
 - `[AsyncMethodBuilder]` (needed for [custom method builder types](https://learn.microsoft.com/dotnet/csharp/language-reference/proposals/csharp-10.0/async-method-builders))
 - `[StringSyntax]` (needed to enable [syntax highlight in the IDE](https://github.com/dotnet/runtime/issues/62505))
 - `[ModuleInitializer]` (needed to enable [custom module initializers](https://learn.microsoft.com/dotnet/csharp/language-reference/proposals/csharp-9.0/module-initializers))
+- `[RequiresLocation]` (needed to enable [ref readonly parameters](https://github.com/dotnet/csharplang/issues/6010))
 
 To leverage them, make sure to bump your C# language version. You can do this by setting the `<LangVersion>` MSBuild property in your project. For instance, by adding `<LangVersion>11.0</LangVersion>` (or your desired C# version) to the first `<PropertyGroup>` of your .csproj file. For more info on this, [see here](https://sergiopedri.medium.com/enabling-and-using-c-9-features-on-older-and-unsupported-runtimes-ce384d8debb), but remember that you don't need to manually copy polyfills anymore: simply adding a reference to **PolySharp** will do this for you automatically.
 

src/PolySharp.SourceGenerators/EmbeddedResources/System.Runtime.CompilerServices.RequiresLocationAttribute.cs

@@ -0,0 +1,20 @@
+// <auto-generated/>
+#pragma warning disable
+#nullable enable annotations
+
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Runtime.CompilerServices
+{
+    /// <summary>
+    /// Reserved for use by a compiler for tracking metadata.
+    /// This attribute should not be used by developers in source code.
+    /// </summary>
+    [global::System.AttributeUsage(global::System.AttributeTargets.Parameter, Inherited = false)]
+    [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    internal sealed class RequiresLocationAttribute : global::System.Attribute
+    {
+    }
+}

src/PolySharp.SourceGenerators/PolyfillsGenerator.TypeForwards.cs

@@ -17,7 +17,8 @@ partial class PolyfillsGenerator
     private static readonly ImmutableArray<string> ModreqCandidateFullyQualifiedTypeNames = ImmutableArray.Create(
         "System.Index",
         "System.Range",
-        "System.Runtime.CompilerServices.IsExternalInit");
+        "System.Runtime.CompilerServices.IsExternalInit",
+        "System.Runtime.CompilerServices.RequiresLocationAttribute");
 
     /// <summary>
     /// Gets the types from the BCL that should potentially receive type forwards.