message: Add comments to explain IndexMap
diff: @@ -120,6 +120,11 @@ impl RunWithPathBuf {
  #[cfg(feature = "wasi")]
  {
  + // See https://github.com/wasmerio/wasmer/issues/3492 -
  + // we need IndexMap to have a stable ordering for the [fs] mapping,
  + // otherwise overlapping filesystem mappings might not work
  + // since we want to control the order of mounting directories from the
  + // wasmer.toml file
  let default = indexmap::IndexMap::default();
  let fs = manifest.fs.as_ref().unwrap_or(&default);
  for (alias, real_dir) in fs.iter() {
  