stage0 新增内存复制指令 重构vm交互

stage2/attr.spl

@@ -202,6 +202,7 @@ fn register_builtins(self: *Attr) {
     registry_add(self, make_info("", "align", .Layout, .Type, .Required, 1, 1));
     registry_add(self, make_info("", "volatile", .Ir, .Expr, .Required, 0, 0));
     registry_add(self, make_info("", "atomic", .Ir, .Expr, .Required, 0, 1));
+    registry_add(self, make_info("", "export", .Ir, .Decl, .Optional, 1, 1));
 }
 
 // ---- dump（镜像 stage1 spl_attr_dump / spl_attr_dump_id）----
@@ -360,7 +361,7 @@ fn test_registry() {
     }
     defer { drop(&at); }
 
-    @assert(at.registry.len == 7, "1 sentinel + 6 builtins");
+    @assert(at.registry.len == 8, "1 sentinel + 7 builtins");
 
     var i = lookup(&at, ByteView.empty(), ByteView.from_slice("extern"));
     @assert(i != 0, "extern found");