refactor: 扁平化对象属性存储并优化常量池与 IC 热路径

crates/oxide_compiler/tests/compile_expr_tests.rs

@@ -52,6 +52,17 @@ fn compile_constants() {
     assert_eq!(module.constants[0], oxide_compiler::compiler::Constant::Int(42));
 }
 
+#[test]
+fn compile_dedups_identical_string_constants() {
+    let module = compile_source("var a = 'hello'; var b = 'hello';");
+    let count = module
+        .constants
+        .iter()
+        .filter(|c| matches!(c, oxide_compiler::compiler::Constant::String(s) if s == "hello"))
+        .count();
+    assert_eq!(count, 1, "identical string constants should be interned once per module");
+}
+
 #[test]
 fn compile_negation() {
     let module = compile_source("-5");