#We #undef __x86_64__ for kernelspace, not for userspace where
#it's needed for headers to work!
-CFLAGS += -U__$(SUBARCH)__ $(_extra_flags_)
-USER_CFLAGS += $(_extra_flags_)
+ARCH_KERNEL_DEFINES = -U__$(SUBARCH)__
+CFLAGS += $(_extra_flags_)
CHECKFLAGS += -m64
AFLAGS += -m64