[Feature Request]: Run llvm Emscripten tests for Interpreter as part of ci

[mcbarton]

Description of new feature

Once we have llvms Emscripten tests PR in, and its part of a release branch (hopefully we can get in llvm 21), we can start running the tests as part of the ci, allowing CppInterOp to know if anything broke for the Emscripten build in llvm.