fix(getTag): (#3820)

IE11: global `toString` can not be called as `Object.prototype.toString`, so we need to use the Object version, like done in lodash (not doing this initially was likely a simple omission)

src/lib/utils/isPlainObject.ts

@@ -8,7 +8,7 @@ function getTag(value: any): string {
     return value === undefined ? '[object Undefined]' : '[object Null]';
   }
 
-  return toString.call(value);
+  return Object.prototype.toString.call(value);
 }
 
 function isObjectLike(value: any): boolean {