Refine the type signatures of the functions apply, call, and bind.

src/lib/es5.d.ts

@@ -260,22 +260,22 @@ interface Function {
      * @param thisArg The object to be used as the this object.
      * @param argArray A set of arguments to be passed to the function.
      */
-    apply(this: Function, thisArg: any, argArray?: any): any;
+    apply<A extends any[], R>(this: (...args: A) => R, thisArg: any, argArray?: A): R;
 
     /**
      * Calls a method of an object, substituting another object for the current object.
      * @param thisArg The object to be used as the current object.
      * @param argArray A list of arguments to be passed to the method.
      */
-    call(this: Function, thisArg: any, ...argArray: any[]): any;
+    call<A extends any[], R>(this: (...args: A) => R, thisArg: any, ...argArray: A): R;
 
     /**
      * For a given function, creates a bound function that has the same body as the original function.
      * The this object of the bound function is associated with the specified object, and has the specified initial parameters.
      * @param thisArg An object to which the this keyword can refer inside the new function.
      * @param argArray A list of arguments to be passed to the new function.
      */
-    bind(this: Function, thisArg: any, ...argArray: any[]): any;
+    bind<A extends any[], R>(this: (...args: A) => R, thisArg: any, ...argArray: A): (...args: A) => R;
 
     /** Returns a string representation of a function. */
     toString(): string;