Add an unrelated type parameter and this parameter

This returns `call` to its previous level of fidelity.
Thanks (?) to @weswigham for this hack.

types/bluebird/bluebird-tests.ts

@@ -553,7 +553,7 @@ bool = fooProm.isResolved();
 strProm = fooProm.call("foo");
 strProm = fooProm.call("foo", 1, 2, 3);
 
-// $ExpectType Bluebird<any>
+// $ExpectType Bluebird<never>
 quxProm.call("qux");
 
 strProm = fooProm.get("foo").then(method => method());

types/bluebird/index.d.ts

@@ -350,7 +350,7 @@ declare class Bluebird<R> implements PromiseLike<R>, Bluebird.Inspection<R> {
    * });
    * </code>
    */
-  call<U extends keyof R>(propertyName: U, ...args: any[]): Bluebird<any>;
+  call<U extends keyof Q, Q>(this: Bluebird<Q>, propertyName: U, ...args: any[]): Bluebird<Q[U] extends (...args: any[]) => any ? ReturnType<Q[U]> : never>;
 
   /**
    * This is a convenience method for doing: