popper: destroy popper instance(#13988)

packages/loading/src/directive.js

@@ -121,6 +121,7 @@ loadingDirective.install = Vue => {
         el.mask.parentNode.removeChild(el.mask);
         toggleLoading(el, { value: false, modifiers: binding.modifiers });
       }
+      el.instance && el.instance.$destroy();
     }
   });
 };

packages/tooltip/src/main.js

@@ -205,6 +205,10 @@ export default {
     }
   },
 
+  beforeDestroy() {
+    this.popperVM && this.popperVM.$destroy();
+  },
+
   destroyed() {
     const reference = this.referenceElm;
     off(reference, 'mouseenter', this.show);