failed to build in x86_64 arch

[fripSide]

I modified the Makefile to build the x86_64 version using:
CROSS_COMPILE = /root/android-ndk-r10e/toolchains/x86_64-4.9/prebuilt/linux-x86_64/bin/x86_64-linux-android-
make ARCH=x86_64 x86_64_defconfig

But something went wrong.

The error message is:
In file included from arch/x86/kernel/traps.c:34:0:
include/linux/nmi.h:8:27: fatal error: asm/core_regs.h: No such file or directory
#include <asm/core_regs.h>
^

[fripSide]

The file mm/early_ioremap.c seems to be redundance.