[steveisok]

Fixes #136264.

The B03689Native.dll and B07847Native.dll C++/CLI helpers are mixed-mode assemblies that Crossgen2 explicitly rejects. Add <CrossGenTest>false</CrossGenTest> and <R2RIncompatible>true</R2RIncompatible> to b03689.csproj and b07847.csproj, matching the related mixed-mode TLS tests updated in #136266.

This prevents unsupported ReadyToRun compilation and skips execution in both ordinary and composite R2R runs. Ordinary JIT coverage remains enabled, and existing compatibility metadata and test assertions are unchanged. This does not change Crossgen2 support.

Validation

• Passed: MSBuild evaluation of both actual projects for Windows x64 and arm64 Checked, plus complete batch and Bash wrapper generation using FetchExternalProperties,GenerateBatchExecutionScript,GenerateBashExecutionScript. All four configurations remain BuildAndRun, with _WillCLRTestProjectBuild=true and GenerateRunScript=true.
• Passed: 16 generated Bash wrapper/control-flow checks using a probe launcher. Ordinary and composite R2R skip successfully before launch; ordinary JIT, including CompositeBuildMode alone without RunCrossGen2, reaches the probe launcher. These checks did not execute the Windows C++/CLI test assertions.
• Passed: Inspection of the generated Windows batch wrappers confirms the R2R skip precedes the unchanged corerun.exe launch. Structural XML comparison confirms all pre-existing project settings and references are preserved. git diff --check passed.
• Not run: Windows binaries were not built or executed on the macOS ARM64 host.

Resolves #136264

Note

This PR description was generated with GitHub Copilot.

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