I am using daily build 2016.2900. And I am using XCode 7.3.
I got email from iTunes recently after I uploaded my build every time. It doesn’t stop my build but I think it is better to fix it. Here is the email content:
Unexpected Machine Code - Your upload contains both bitcode and native machine code. When you provide bitcode, it’s not necessary to include machine code as well. To reduce the size of your upload, use Xcode 7.3 or later, or any other toolchain that removes machine code.