This reverts commit 519a199cbc.
Multiple users have reported building failures on ARM architectures, e.g.:
In file included from defs.h:42:0,
from process.c:37:
process.c:51:22: error: 'struct user_regs' has no member named 'ARM_r0'
#define uoff(member) offsetof(struct user, member)
^
./linux/arm/userent.h:1:3: note: in expansion of macro 'uoff'
{ uoff(regs.ARM_r0), "r0" },
^
Signed-off-by: Jo-Philipp Wich <jo@mein.io>