refactor: centralize box type metadata

src/backend/llvm/compiler/mock.rs

@@ -0,0 +1,8 @@
+use super::LLVMCompiler;
+use crate::box_trait::{BoolBox, IntegerBox, NyashBox, StringBox};
+use crate::boxes::{function_box::FunctionBox, math_box::FloatBox, null_box::NullBox};
+use crate::mir::function::MirModule;
+use crate::mir::instruction::{BinaryOp, ConstValue, MirInstruction};
+use std::collections::HashMap;
+
+include!("mock_impl.in.rs");