message: js: Fix reactor interface to not use Emscripten imports
  We now create the array wrapper for each decode which should be
  almost free, to avoid having to use a non-standard sbrk interface.
diff: @@ -28,20 +28,13 @@ var MeshoptDecoder = (function() {
  console.log("Warning: meshopt_decoder is using experimental SIMD support");
  }
  - var instance, heap;
  -
  - var env = {
  - emscripten_notify_memory_growth: function(index) {
  - heap = new Uint8Array(instance.exports.memory.buffer);
  - }
  - };
  + var instance;
  var promise =
  - WebAssembly.instantiate(unpack(wasm), { env })
  + WebAssembly.instantiate(unpack(wasm), {})
  .then(function(result) {
  instance = result.instance;
  - instance.exports._initialize();
  - env.emscripten_notify_memory_growth(0);
  + instance.exports.__wasm_call_ctors();
  });
  function unpack(data) {
  @@ -62,6 +55,7 @@ var MeshoptDecoder = (function() {
  var count4 = (count + 3) & ~3; // pad for SIMD filter
  var tp = sbrk(count4 * size);
  var sp = sbrk(source.length);
  + var heap = new Uint8Array(instance.exports.memory.buffer);
  heap.set(source, sp);
  var res = fun(tp, count, size, sp, source.length);
  if (res == 0 && filter) {
  