Support cross-arch execve from ARM to AArch64 and vice versa

Created by: ghost

Hi, I'm currently working on an "Android on Android" project which aims to provide a separate Android environment inside an app. We've run into some problems on 64-bit Android builds because many system binaries & other apps are still targeting 32-bit but 64-bit build of DynamoRIO cannot handle them (ERROR: Target process is for the wrong architecture). What's the possible solution here other than shipping 32-bit Android binaries & support only 32-bit apps?