fixed build errors

Author: EthanBerko32

crates/dfg_passes/src/builder.rs

@@ -58,6 +58,12 @@ impl DfgBuilder {
     }
 }
 
+impl Default for DfgBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 macro_rules! dfg_index_impl {
     ($field:ident, $idx:ty, $out:ty) => {
         impl Index<$idx> for DfgBuilder {

crates/dfg_passes/src/dfg_passes.rs

@@ -17,6 +17,7 @@ pub fn pass(dfg: &mut Dfg) -> Result<(), &'static str> {
 fn parse_operator(op: ArithOp) {
     match op {
         ArithOp::Sin => {}
-        _ => return,
+        ArithOp::Cos => {}
+        _ => (),
     }
 }