Fix hw1 fuzzer again

src/opt/mem2reg.rs

@@ -1,11 +1,14 @@
-use crate::ir;
+use crate::ir::*;
+use crate::opt::FunctionPass;
 use crate::*;
 
-#[derive(Default)]
-pub struct Mem2reg {}
+pub type Mem2reg = FunctionPass<Mem2regInner>;
 
-impl Optimize<ir::TranslationUnit> for Mem2reg {
-    fn optimize(&mut self, _code: &mut ir::TranslationUnit) -> bool {
-        todo!()
+#[derive(Default)]
+pub struct Mem2regInner {}
+
+impl Optimize<FunctionDefinition> for Mem2regInner {
+    fn optimize(&mut self, _code: &mut FunctionDefinition) -> bool {
+        todo!("homework 4")
     }
 }