Add some mathematical functions: sin, cos, ...
Support sin, cos, atan2 by following commit:
commit e529f3c4347e97671635c0daa87040dcb1793e33 (HEAD -> master, origin/master, origin/HEAD) Author: Steel Wheels Project <wheel@tcn.zaq.ne.jp> Date: Sat Mar 16 10:01:15 2019 +0900 KiwiLibrary: Add built-in functions for mathematics
Add built-in mathematical functions.