Add code fixer for MA0173 (Use LazyInitializer.EnsureInitialized)

[Copilot]

MA0173 flagged Interlocked.CompareExchange(ref _field, new T(), null) but provided no automated fix.

Changes

• New fixer UseLazyInitializerEnsureInitializeFixer: rewrites the flagged call to LazyInitializer.EnsureInitialized, wrapping the factory expression in a lambda and dropping the null comparand argument. Supports fix-all via BatchFixer.
• Tests: wired up the fixer in the existing test builder and added ShouldFixCodeWith assertions for the four diagnostic cases.
• Docs: README code-fix column for MA0173 updated from ❌ to ✔️ (auto-generated).

Example

// Before
Interlocked.CompareExchange(ref _field, new Sample(), null);

// After
System.Threading.LazyInitializer.EnsureInitialized(ref _field, () => new Sample());

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• 1s1vsblobprodcus386.vsblob.vsassets.io
  • Triggering command: /usr/share/dotnet/dotnet dotnet restore --no-dependencies /home/REDACTED/work/Meziantou.Analyzer/Meziantou.Analyzer/Meziantou.Analyzer.slnx --packages /tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/packages /p:DisableImplicitNuGetFallbackFolder=true --verbosity normal /p:TargetFrameworkRootPath=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:NetCoreTargetingPackRoot=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:AllowMissingPrunePackageData=true (dns block)
• pdfvsblobprodcus380.vsblob.vsassets.io
  • Triggering command: /usr/share/dotnet/dotnet dotnet restore --no-dependencies /home/REDACTED/work/Meziantou.Analyzer/Meziantou.Analyzer/Meziantou.Analyzer.slnx --packages /tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/packages /p:DisableImplicitNuGetFallbackFolder=true --verbosity normal /p:TargetFrameworkRootPath=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:NetCoreTargetingPackRoot=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:AllowMissingPrunePackageData=true (dns block)
• st8vsblobprodcus339.vsblob.vsassets.io
  • Triggering command: /usr/share/dotnet/dotnet dotnet restore --no-dependencies /home/REDACTED/work/Meziantou.Analyzer/Meziantou.Analyzer/Meziantou.Analyzer.slnx --packages /tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/packages /p:DisableImplicitNuGetFallbackFolder=true --verbosity normal /p:TargetFrameworkRootPath=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:NetCoreTargetingPackRoot=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:AllowMissingPrunePackageData=true (dns block)
  • Triggering command: /usr/share/dotnet/dotnet dotnet restore --no-dependencies /home/REDACTED/work/Meziantou.Analyzer/Meziantou.Analyzer/tests/Meziantou.Analyzer.Test/Meziantou.Analyzer.Test.csproj --packages /tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/packages /p:DisableImplicitNuGetFallbackFolder=true --verbosity normal /p:TargetFrameworkRootPath=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:NetCoreTargetingPackRoot=/tmp/codeql-scratch-8ad8dc5536a632e8/dbs/csharp/working/emptyFakeDotnetRoot /p:AllowMissingPrunePackageData=true (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)