sh: arc: cmpxchg.h:50:12: error: implicit declaration of function 'cmpxchg_emu_u8' [-Werror=implicit-function-declaration]

[Naresh Kamboju]

The arc and sh defconfig builds failed due to following build warnings / errors
on the Linux next-20240415 with gcc-9 and gcc-11.

Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>

Following builds failed.
sh:
arc:
 - defconfig
 - tinyconfig
 - allnoconfig
 - vdk_hs38_smp_defconfig

Build log:
--------
In file included from arch/arc/include/asm/atomic.h:13,
                 from include/linux/atomic.h:7,
                 from include/asm-generic/bitops/lock.h:5,
                 from arch/arc/include/asm/bitops.h:188,
                 from include/linux/bitops.h:70,
                 from include/linux/log2.h:12,
                 from kernel/bounds.c:13:
include/linux/atomic/atomic-arch-fallback.h: In function 'raw_atomic_cmpxchg':
arch/arc/include/asm/cmpxchg.h:50:12: error: implicit declaration of
function 'cmpxchg_emu_u8' [-Werror=implicit-function-declaration]
   50 |   _prev_ = cmpxchg_emu_u8((volatile u8 *)_p_, _o_, _n_); \
      |            ^~~~~~~~~~~~~~

Steps to reproduce:
---
# tuxmake --runtime podman --target-arch arc --toolchain gcc-9
--kconfig defconfig
# tuxmake --runtime podman --target-arch sh --toolchain gcc-11
--kconfig defconfig


Links:
---
 - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240415/testrun/23463978/suite/build/test/gcc-9-defconfig/details/
 - https://storage.tuxsuite.com/public/linaro/lkft/builds/2f7sIl2MlKB5Fgq7JtTpYQ9lnXw/
 - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240415/testrun/23463981/suite/build/test/gcc-11-defconfig/details/


--
Linaro LKFT
https://lkft.linaro.org