Buffer Lib does not transpile code into ES2015 which does not allow to import it by older devices

On our project, we faced an issue of having a non-tranpiled `const` in `node_modules`. This is an issue for us as some of the devices we support end up not working due to a transpilation error.

As a fix on our side, we have to fork `buffer` lib locally and transpile it ourselves so that all `const` become `var` and other ES2015 syntax (we are also a lib used by the apps, so transpiling buffer code via webpack was not an option).

Is it possible to solve it on the `buffer` side and compile contents to ES2015 so we can import `buffer` again?