Add a conversion from our high-level IR to a lower-level one.

src/passes.rs

@@ -1,12 +1,13 @@
-use codespan_reporting::files::SimpleFiles;
 use crate::asts::hil;
 use crate::errors::Error;
 use crate::syntax;
 use crate::syntax::Location;
 use crate::variable_map::VariableMap;
 use crate::warnings::Warning;
+use codespan_reporting::files::SimpleFiles;
 use std::fs;
 
+mod hil_to_lil;
 mod syntax_to_hil;
 
 pub struct PassResult<T> {
@@ -15,9 +16,9 @@ pub struct PassResult<T> {
     pub errors: Vec<Error>,
 }
 
-impl<T,E> From<E> for PassResult<Option<T>>
- where
-  Error: From<E>
+impl<T, E> From<E> for PassResult<Option<T>>
+where
+    Error: From<E>,
 {
     fn from(x: E) -> Self {
         PassResult {
@@ -61,4 +62,4 @@ pub fn run_front_end(
         warnings: conversion_result.warnings,
         errors: conversion_result.errors,
     }
-}
+}