Pull request #3302: 无JIRA fix: extend 类型修复

Merge in VISUAL/fineui from ~SYLAR/fineui:master to master

* commit '51c1b860d6d907aad4dbb4d6f0555d662db84b64':
  无JIRA fix: extend 类型修复

typescript/core/base.ts

@@ -178,7 +178,7 @@ export interface _base {
     functions: (object: object) => string[];
 
     extend<T extends object>(object: T): T;
-    extend<T extends object, U>(object: T, ...sources: U[]): T & UnionToIntersection<NonNullable<U>>;
+    extend<T extends object, U extends unknown[]>(object: T, ...sources: U): T & UnionToIntersection<NonNullable<U[number]>>;
 
     defaults: (object: object, ...sources: any[]) => object;