The textures on the spider leg models aren't mirrored properly

Related to MC-127885. (parity issue)

The textures for the spider leg models are not mirrored properly.

How to Reproduce
1. Download the attached resource pack and enable it.
2. Check the legs if it's mirrored correctly.

Observed Result
The spider leg model textures are mirrored incorrectly.

Expected Result
The spider leg model textures are mirrored correctly.