[fine] test compilation, start removing print

fine/build.rs

@@ -37,6 +37,21 @@ fn generate_test_for_file(path: PathBuf) -> String {
             assertions.push(quote! {
                 crate::assert_concrete(&_tree, #concrete, #display_path);
             });
+        } else if line == "@compiles-to:" {
+            let mut compiled = String::new();
+            while let Some(line) = lines.next() {
+                let line = match line.strip_prefix("// | ") {
+                    Some(line) => line,
+                    None => break,
+                };
+
+                compiled.push_str(line);
+                compiled.push_str("\n");
+            }
+
+            assertions.push(quote! {
+                crate::assert_compiles_to(&_tree, &_lines, #compiled, #display_path);
+            });
         } else if let Some(line) = line.strip_prefix("@type:") {
             let (pos, expected) = line
                 .trim()