[PATCH] [ASAN/AArch64] Fix kernel_old_Xid_t type

[Christophe Lyon]

>>! In D6026#6, @kcc wrote:
> We deliberately do not include system headers into this file. 

Could you explain the reasons for this choice in more detail?
Maybe there is a design documentation publicly available?

> I know this is causing a maintenance nightmare, but other choice are worse.  
What other choices are you thinking of?

http://reviews.llvm.org/D6026