feat(tvix/eval): add initial chunk representation

Change-Id: I53202e93938bede421c8f1c98901e4c67544e257
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6069
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>

tvix/eval/src/main.rs

@@ -4,6 +4,7 @@ use std::{
     mem, process,
 };
 
+mod chunk;
 mod errors;
 mod eval;
 mod opcode;