Fix parsing of symbol table

src/output.rs

@@ -2,7 +2,7 @@ use std::collections::BTreeMap;
 
 use eyre::{bail, Context};
 use serde::Serialize;
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 #[derive(Default)]
 pub struct Output {
@@ -17,6 +17,22 @@ impl Output {
         }
         Ok(())
     }
+
+    pub fn write_append(&mut self, key: &'static str, v: &impl Serialize) -> eyre::Result<()> {
+        let Value::Object(mut v) =
+            serde_json::to_value(v).wrap_err("failed to serialize output")?
+        else {
+            bail!("tried to append non-object");
+        };
+
+        let Value::Object(entry) = self.elements.entry(key).or_insert(Map::new().into()) else {
+            bail!("tried to append to non-object");
+        };
+
+        entry.append(&mut v);
+
+        Ok(())
+    }
 }
 
 impl Drop for Output {