https://github.com/juj/emsdk @ 2324e5d8
LLVM_CMAKE_ARGS="-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=WebAssembly" emsdk install sdk-tag-1.37.28-64bit
(be patient!)
To activate correct paths for emscripten and dependencies use:
./emsdk activate sdk-tag-1.37.28-64bit
./emsdk_env.sh