[PATCH] [ASAN/AArch64] Fix kernel_old_Xid_t type

[Christophe Lyon]

I cannot test other architectures, but this inclusion of linux/posix_types.h would lead to further cleanup in sanitizer_platform_limits_posix.h, starting with the types being discussed here: __kernel_old_gid_t and __kernel_old_uid_t

Only:
typedef __kernel_old_uid_t __sanitizer___kernel_old_uid_t;
typedef __kernel_old_gid_t __sanitizer___kernel_old_gid_t;
would probably be sufficient for all architectures, instead of the current:
#if defined(__powerpc__) || defined(__mips__)
  typedef unsigned int __sanitizer___kernel_old_uid_t;
  typedef unsigned int __sanitizer___kernel_old_gid_t;
#else
  typedef unsigned short __sanitizer___kernel_old_uid_t;
  typedef unsigned short __sanitizer___kernel_old_gid_t;
#endif

http://reviews.llvm.org/D6026