Suggest moving `abs()` to a more appropriate source file

[weiso131]

Currently, the implementation of abs() is located in lib/memory.c, which is primarily intended for memory manipulation functions. However, abs() is a mathematical utility function, so its placement here feels semantically inconsistent.

While this does not affect functionality, from a code organization and maintainability perspective, it might be worth considering moving abs() to a more suitable location, such as a new lib/math.c file. This could also provide a clear place to add other math-related functions in the future.

[jserv]

While this does not affect functionality, from a code organization and maintainability perspective, it might be worth considering moving abs() to a more suitable location, such as a new lib/math.c file.

Agree. Send a pull request.