Fix managed IID_PPV_ARGS overloads for native COM out pointers

[littletoxic]

Summary

• Treat IID_PPV_ARGS overloads as managed when AllowMarshaling is enabled, even when the extern ppv parameter remains native void**.
• Convert native COM out pointers to managed T for both source-generated and built-in COM paths.
• Add regression coverage for ID3D12Device.CreateCommittedResource, including build-task generation.

Fixes #1608

Notes

CreateCommittedResource marks ppvResource as optional, and native callers may pass nullptr for capability testing. This PR intentionally does not add a generic friendly overload that omits ppvResource; it only fixes the existing IID_PPV_ARGS generic overload so AllowMarshaling=true produces out T where T : class. Please let me know if you would prefer adding an omitted-output friendly overload as well.

This PR was created with assistance from Codex.

Validation

Local targeted validation was run with NBGV_GitEngine=Disabled. I did not run the full local test suite because the PR CI covers the full Windows/Linux and heavy-test matrix.

• dotnet build src\CsWin32Generator\CsWin32Generator.csproj --no-restore
  • Passed; observed an existing PrimitiveTypeHandleInfo.cs CS9336 warning under local SDK 10.0.301.
• dotnet test test\Microsoft.Windows.CsWin32.Tests\Microsoft.Windows.CsWin32.Tests.csproj --no-restore --filter "FullyQualifiedName~ComOutPtrGenericOverload"
  • Passed: 11 tests.
• dotnet test test\GenerationSandbox.BuildTask.Tests\GenerationSandbox.BuildTask.Tests.csproj --no-restore --filter "FullyQualifiedName~ID3D12Device_CreateCommittedResource_GenericOverloadsCompile"
  • Passed for net9.0-windows10.0.22621.0 and net10.0-windows10.0.22621.0.

[littletoxic]

@microsoft-github-policy-service agree

[jevansaks]

Thanks @littletoxic for the contribution! I'll take a look.