Pipeline should bundle all parts of generated with the same type instead of only the last

[DeMoorJasper]

🐛 bug report

The asset pipeline drops the first JS output from generated if a second one is also in the generated Array.
This mainly occurs when having an asset that has both css and js, as in hmr mode css adds a js file to the generated array

🎛 Configuration (.babelrc, package.json, cli command)

Zero Config, using parcel-plugin-svelte

🤔 Expected Behavior

Should add both scripts to the bundle

😯 Current Behavior

Adds the latest script to the bundle

💁 Possible Solution

Create a seperate HMR bundle that gets added to the html in a seperate script tag that replaces scripts, css and reloads html. Instead of bundling inside asset bundles.

Or add the ability to add options to the generated assets, to prevent css from creating hmr code. Or something similar to addUrlDependency includedInParent

🔦 Context

DeMoorJasper/parcel-plugin-svelte#15

💻 Code Sample

DeMoorJasper/parcel-plugin-svelte#15

🌍 Your Environment

Software	Version(s)
Parcel	1.8.1
Node	v10
npm/Yarn	latest
Operating System	OS X High Sierra