fix(popup): popper target element selection logic

fix(menu): fix menu item auto-flip failure

Author: RSS1102

src/popup/popup.tsx

@@ -194,13 +194,16 @@ export default mixins(classPrefixMixins, getAttachConfigMixins('popup')).extend(
     updatePopper() {
       const { $el: triggerEl } = this;
       const popperEl = this.$refs.popper as HTMLElement;
+      const overlayEl = this.$refs.overlay as HTMLElement;
+      const popperTargetEl = overlayEl || popperEl;
+
+      if (!popperTargetEl || !this.visible) return;
 
-      if (!popperEl || !this.visible) return;
       if (this.popper) {
         this.popper.update();
         return;
       }
-      this.popper = createPopper(triggerEl, popperEl, {
+      this.popper = createPopper(triggerEl, popperTargetEl, {
         modifiers:
           getIEVersion() > 9
             ? []