feat(ast2ir): 实现C11类型提升系统并重构HIR基本块管理

- 新增 scc_ast2ir_promote.c 实现整数提升(6.3.1.1)和寻常算术转换(6.3.1.8)
- 重构 HIR Builder: bblock → create_bblock + append_bblock，引入BBList链表管理
- AST2IR 全面集成类型提升：二元运算、赋值、函数调用参数、自增/自减操作符
- 变参函数支持：跳过 ... 假参数，实现默认参数提升(float→double等)
- 简化 HIR Dump 实现
- MIR: Win64 ABI改进、x86指令选择优化
- 新增 printf 测试用例

libs/mcode/include/x86/scc_x86_patch.h

@@ -120,11 +120,11 @@ static inline int scc_x86_patch_imm0_ex(scc_mcode_t *mcode, usize offset,
 
 static inline void scc_x86_patch(scc_mcode_t *mcode,
                                  scc_x86_patch_type_t patch_type, u64 offset,
-                                 i64 value) {
+                                 u64 value) {
     switch (patch_type) {
     case SCC_X86_PATCH_PC32:
-        scc_x86_patch_brdisp(mcode, offset - 4,
-                             scc_x86_op_relbr(value - offset));
+        i32 rel = value - offset;
+        scc_x86_patch_brdisp(mcode, offset - 4, scc_x86_op_relbr(rel));
         break;
     default:
         TODO();

libs/mcode/src/scc_x86_encode.c

@@ -218,9 +218,13 @@ static int scale_to_enc(uint8_t scale) {
 
 /* 修正：位移大小只由数值范围决定，与基址寄存器无关 */
 static int disp_size(int32_t disp, scc_x86_reg_t base) {
-    (void)base;
-    if (disp == 0)
+    if (disp == 0) {
+        /* RBP/R13 with disp=0: must use mod=01 + disp8=0,
+           because mod=00 + r/m=101 means RIP-relative */
+        if (base == SCC_X86_REG_RBP || base == SCC_X86_REG_R13)
+            return 8;
         return 0;
+    }
     if (disp >= -128 && disp <= 127)
         return 8;
     return 32;
@@ -496,10 +500,12 @@ int scc_x86_encode_inst(scc_mcode_t *mcode, scc_x86_iform_t iform,
         } else if (ops[i].kind == SCC_X86_OPR_MEM) {
             base_reg = ops[i].mem.base;
             idx_reg = ops[i].mem.index;
-        } else if (ops[i].kind == SCC_X86_OPR_IMM ||
-                   ops[i].kind == SCC_X86_OPR_RELBR) {
+        } else if (ops[i].kind == SCC_X86_OPR_IMM) {
             imm_val = ops[i].imm0;
             imm_idx = i;
+        } else if (ops[i].kind == SCC_X86_OPR_RELBR) {
+            imm_val = ops[i].brdisp; // i32 → i64 自动符号扩展
+            imm_idx = i;
         }
     }