Steps to replicate the issue (include links if applicable):

• Create the following module:

skin.json

		"testit": {
			"class": "MediaWiki\\ResourceLoader\\CodexModule",
			"styles": [
				"resources/test.less"
			]
		},

test.less

div {
    position: absolute;
    left: 0;
}

• Visit http://localhost:8888/w/load.php?lang=fa&modules=testit&only=styles

What happens?:
CSS is not flipped.

div{position:absolute;left:0}.

What should have happened instead?:
CSS should be flipped.

div{position:absolute;right: 0}.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):