General improvements to Emscripten build and ci#533

mcbarton merged 2 commits intocompiler-research:maincompiler-research/CppInterOp:mainfrom

mcbarton:Remove-NATIVE-folder-Emscripten-llvm-buildmcbarton/CppInterOp:Remove-NATIVE-folder-Emscripten-llvm-buildCopy head branch name to clipboard