stage0 新增内存复制指令 重构vm交互

stage1/spl_ir2vm.c

@@ -1016,10 +1016,7 @@ static void cg_control(cgen_t *cg, usize ref, const spl_ir_node_t *n) {
                 CG_LOAD(cg, SPL_PTR);
                 cg_load_slot(cg, n->control_ret.val, SPL_PTR);
                 CG_PUSH(cg, SPL_U64, sz);
-                int nat = get_or_add_native(ctx, "vm_memcpy");
-                CG_PUSH(cg, SPL_U64, (spl_vm_val_t)nat);
-                emit(cg, SPL_NCALL, SPL_VOID, 3);
-                emit(cg, SPL_DROP, SPL_VOID, 0);
+                emit(cg, SPL_MEMCPY, SPL_VOID, 0);
             }
             emit(cg, SPL_RET, SPL_VOID, 0);
             break;