某些第三方API缺少64位支持的解决办法(从CocoaChina问答中转载)

在开发QQ第三方登录使用64位模拟器和iPhone 5s做测试的时候遇到如下错误:
Undefined symbols for architecture x86_64:

  "_OBJC_CLASS_$_TencentOAuth", referenced from:

      objc-class-ref in ViewController.o

      objc-class-ref in AppDelegate.o

  "l_OBJC_PROTOCOL_$_TencentApiInterfaceDelegate", referenced from:

      l_OBJC_$_PROTOCOL_REFS_TencentSessionDelegate in ViewController.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

具体解决方法如下: 
红色方框中原来是 $(ARCHS_STANDARD),改成$(ARCHS_STANDARD_32_BIT),即只支持32位的即可.