Self-chained selectors are flattened

[tbredin]

Sometimes we want to chain a class selector with itself for a low-risk specificity increase. Why?
Details here: https://csswizardry.com/2014/07/hacks-for-dealing-with-specificity/#safely-increasing-specificity

eg
This scss:

.social__icon.social__icon { // require specificity to override
	// stuff
}

results in this css:

.social__icon {
	// stuff
}

So right now the chaining gets removed and we end up with a single low specify single class. Weird! Not sure why these are getting flattened, might be part of minification? Needs investigation