Add XuanTie extensions.

Including the following XuanTie extensions:

1. Add XuanTie CBI/CF/CV extension
2. Add XuanTie VSFA extensions
3. Add XuanTie VSFB extensions
4. Add XuanTie AIOE extensions
5. Add XuanTie CBOP extensions
6. Add XuanTie VARITH extensions
7. Add XuanTie VCODER extensions
8. Add XuanTie VCRYPTO extensions
9. Add XuanTie VDOT extensions
10. Add XuanTie Vector OCP FP8 extensions
11. Add XuanTie Vector OCP E8M0 extensions
12. Add XuanTie Vector OCP FP4 extensions
13. Add XuanTie Vector OCP FP6 extensions
14. Add XuanTie CRC extensions