feat(ast2ir): 添加数组初始化支持和AST转IR优化

添加了对未知长度数组的自动长度推导功能，支持字符串字面量和复合
初始化的数组长度计算。新增辅助函数resolve_array_length用于计算
数组实际长度，以及emit_array_initialization用于生成数组初始化
代码。

同时将AST转IR过程中的参数改为const引用，提高代码安全性。
新增IR构建器的借用检查机制，防止在借用期间进行重分配操作。

fix(ast): 为AST结构体添加详细注释说明字段用途

libs/sccf/include/sccf_builder.h

@@ -21,6 +21,11 @@ usize sccf_builder_add_symbol(sccf_builder_t *builder, const char *name,
                               sccf_sym_t *sym);
 usize sccf_builder_get_symbol_idx(sccf_builder_t *builder, const char *name);
 
+static inline void sccf_builder_set_entry_symbol_name(sccf_builder_t *builder,
+                                                      const char *name) {
+    builder->entry_symbol_name = name ? name : "_scc_entry";
+}
+
 static inline sccf_sym_t *
 sccf_builder_get_symbol_unsafe(sccf_builder_t *builder, const char *name) {
     usize idx = sccf_builder_get_symbol_idx(builder, name);

libs/sccf/src/sccf_builder.c

@@ -75,7 +75,9 @@ const sccf_t *sccf_builder_to_sccf(sccf_builder_t *builder) {
         sccf_sym_t *sym =
             sccf_builder_get_symbol_unsafe(builder, builder->entry_symbol_name);
         if (sym == nullptr || sym->sccf_sect_type != SCCF_SECT_CODE) {
-            LOG_ERROR("entry symbol %s not found");
+            LOG_ERROR(
+                "entry symbol %s not found, using 0 for entry point address",
+                builder->entry_symbol_name);
             builder->sccf.header.entry_point = 0;
         } else {
             builder->sccf.header.entry_point = sym->sccf_sect_offset;