Add Roslyn analyzer and code fix for unique ownership

Introduce a Roslyn analyzer to enforce unique ownership semantics for structs marked with the `[NonCopyable]` attribute. Added a corresponding code fix to resolve violations by suggesting the use of `Share()` or other ownership transfer methods.

Key changes:
- Added `StructCopyCodeAnalyzer` to detect invalid struct copies.
- Implemented `StructCopyCodeFixProvider` to provide code fixes.
- Created `Misaki.HighPerformance.Analyzer` and `CodeFixes` projects.
- Added unit tests for the analyzer and code fixes.
- Introduced `UniquePtr<T>` and `SharedPtr<T>` for pointer ownership.
- Added a Visual Studio extension project and packaging support.
- Updated `UnsafeUtility` to use `nint`/`nuint` for indices.

Misaki.HighPerformance.Analyzer/Misaki.HighPerformance.Analyzer.Vsix/Misaki.HighPerformance.Analyzer.Vsix.csproj

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project>
+  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.props" />
+
+  <PropertyGroup>
+    <TargetFramework>net472</TargetFramework>
+    <RootNamespace>Misaki.HighPerformance.Analyzer.Vsix</RootNamespace>
+    <AssemblyName>Misaki.HighPerformance.Analyzer.Vsix</AssemblyName>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <GeneratePkgDefFile>false</GeneratePkgDefFile>
+    <IncludeAssemblyInVSIXContainer>false</IncludeAssemblyInVSIXContainer>
+    <IncludeDebugSymbolsInVSIXContainer>false</IncludeDebugSymbolsInVSIXContainer>
+    <IncludeDebugSymbolsInLocalVSIXDeployment>false</IncludeDebugSymbolsInLocalVSIXDeployment>
+    <CopyBuildOutputToOutputDirectory>false</CopyBuildOutputToOutputDirectory>
+    <CopyOutputSymbolsToOutputDirectory>false</CopyOutputSymbolsToOutputDirectory>
+    <VSSDKTargetPlatformRegRootSuffix>Roslyn</VSSDKTargetPlatformRegRootSuffix>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.VSSDK.BuildTools" Version="16.8.3038" PrivateAssets="all" />
+  </ItemGroup>
+
+  <PropertyGroup>
+    <StartAction>Program</StartAction>
+    <StartProgram>$(DevEnvDir)devenv.exe</StartProgram>
+    <StartArguments>/rootsuffix $(VSSDKTargetPlatformRegRootSuffix)</StartArguments>
+  </PropertyGroup>
+
+  <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
+
+  <Import Project="$(VSToolsPath)\VSSDK\Microsoft.VsSDK.targets" Condition="Exists('$(VSToolsPath)\VSSDK\Microsoft.VsSDK.targets')" />
+
+  <ItemGroup>
+    <ProjectReference Include="..\Misaki.HighPerformance.Analyzer.CodeFixes\Misaki.HighPerformance.Analyzer.CodeFixes.csproj" />
+    <ProjectReference Include="..\Misaki.HighPerformance.Analyzer\Misaki.HighPerformance.Analyzer.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- https://github.com/dotnet/sdk/issues/433 -->
+    <ProjectReference Update="@(ProjectReference)" AdditionalProperties="TargetFramework=netstandard2.0" />
+
+    <!-- https://github.com/Microsoft/extendvs/issues/57 -->
+    <ProjectReference Update="@(ProjectReference)" Name="%(Filename)" />
+  </ItemGroup>
+
+</Project>

Misaki.HighPerformance.Analyzer/Misaki.HighPerformance.Analyzer.Vsix/source.extension.vsixmanifest

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<PackageManifest Version="2.0.0" xmlns="http://schemas.microsoft.com/developer/vsx-schema/2011" xmlns:d="http://schemas.microsoft.com/developer/vsx-schema-design/2011">
+  <Metadata>
+    <Identity Id="Misaki.HighPerformance.Analyzer.11c300de-143d-4a1e-96bd-d946c0b5f452" Version="1.0" Language="en-US" Publisher="Misaki"/>
+    <DisplayName>Misaki.HighPerformance.Analyzer</DisplayName>
+    <Description xml:space="preserve">This is a sample diagnostic extension for the .NET Compiler Platform ("Roslyn").</Description>
+  </Metadata>
+  <Installation>
+    <InstallationTarget Id="Microsoft.VisualStudio.Community" Version="[15.0,)" />
+  </Installation>
+  <Dependencies>
+    <Dependency Id="Microsoft.Framework.NDP" DisplayName="Microsoft .NET Framework" d:Source="Manual" Version="[4.5,)" />
+  </Dependencies>
+  <Assets>
+    <Asset Type="Microsoft.VisualStudio.MefComponent" d:Source="Project" d:ProjectName="Misaki.HighPerformance.Analyzer" Path="|Misaki.HighPerformance.Analyzer|"/>
+    <Asset Type="Microsoft.VisualStudio.Analyzer" d:Source="Project" d:ProjectName="Misaki.HighPerformance.Analyzer" Path="|Misaki.HighPerformance.Analyzer|"/>
+    <Asset Type="Microsoft.VisualStudio.MefComponent" d:Source="Project" d:ProjectName="Misaki.HighPerformance.Analyzer.CodeFixes" Path="|Misaki.HighPerformance.Analyzer.CodeFixes|"/>
+    <Asset Type="Microsoft.VisualStudio.Analyzer" d:Source="Project" d:ProjectName="Misaki.HighPerformance.Analyzer.CodeFixes" Path="|Misaki.HighPerformance.Analyzer.CodeFixes|"/>
+  </Assets>
+  <Prerequisites>
+    <Prerequisite Id="Microsoft.VisualStudio.Component.CoreEditor" Version="[15.0,)" DisplayName="Visual Studio core editor" />
+    <Prerequisite Id="Microsoft.VisualStudio.Component.Roslyn.LanguageServices" Version="[15.0,)" DisplayName="Roslyn Language Services" />
+  </Prerequisites>
+</PackageManifest>