When there're other preloads and the check for process-shim returns true, `process.env` is added to the end of the vector of all preloads.
That causes problems when one of the previous preloads requires something that checks `process.env` during loading.
E.g. I have a Reagent application with `:npm-deps` set to React and a few other libraries. And I have a preload exactly like this one: https://github.com/flexsurfer/re-frisk/blob/master/src/re_frisk/preload.cljs
The issue is that `re-frisk.core` requires Reagent, which requires React, which checks `process.env` - all before `process.env` was actually created.
I think that `process.env` should go before all existing preloads.