An ancient Indian martial art that includes yoga: https://en.wikipedia.org/wiki/Kalaripayattu
"The foundation of modern Asian martial arts is likely a blend of early Chinese and Indian martial arts." - https://en.wikipedia.org/wiki/Martial_arts#Historical_martia...
But the term "yoga" was historically applied to many sorts of disciplines, both mental and physical. It is likely that Patanjali's sutras were largely general knowledge in ancient India as ways to stay fit and limber, basically like the calisthenics everyone does today.
So it's likely it would have been integrated as part of any physical training regimens that came out of India. So basically, the yoga techniques and postures would be part of the martial arts training in the same way push ups and jumping jacks are.
You must be referring to the Hatha Yoga Pradipika or Gheranda Samhita since PYS doesnt deal with individual asanas/gymnastic yoga whatsoever?
PYS is split into 4 parts: 1. Details regarding superconscious states (samadhi), 2. The means of practice by which samadhi can be attained, 3. the supernatural powers associated with and attained via samadhi including their dangers and pitfalls, 4. how to transcend all the lower samadhis and attain final and complete liberation.
Asanas are only mentioned in the 2nd part and in that context only really mean how to sit properly to attain deep meditation. Gymnastic yoga is nowhere to be found in the book.
Tai Chi on the other hand used to be a martial art and essentially moved into the same space as Yoga.