Some armv7-m-based SoCs do not work with atomic instructions,
even though armv7-m supports them.
To avoid using atomic instructions generated by gcc,
CONFIG_LIBC_ARCH_ATOMIC is newly introduced with which
arch_atomic.c is linked explicitly.
However, the function names need to be changed to avoid
build errors, since the functions described in stdatomic.h
are gcc built-in and inlined when the code is compiled.
About libcxx with CONFIG_LIBC_ARCH_ATOMIC, it still
does not work. It is also needed to call nx_atomic_ ver
instead of __atomic ver in
libcxx/include/__atomic/cxx_atomic_lmpl.h.
Signed-off-by: Takuya Miyasita <Takuya.Miyashita@sony.com>
2275138dcf