He makes many good points in his criticism but I'm still wondering what language one's supposed to use if not C. My lisp has a conservative mark-and-sweep garb

He makes many good points in his criticism but I'm still wondering what language one's supposed to use if not C. My lisp has a conservative mark-and-sweep garbage collector. The mark phase spills all registers and then walks the entire stack looking for pointers to lisp objects. I managed to implement the stack walking through some convoluted pointer nonsense but even C could not express the notion of spilling registers, I had to write assembly code for each architecture. I have no idea how such a garbage collector would be implemented in Rust or Zig.