Determining if the newlocale exist failed with the following output:
Change Dir: /home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make cmTC_83980/fast && make[1]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp'
/usr/bin/make -f CMakeFiles/cmTC_83980.dir/build.make CMakeFiles/cmTC_83980.dir/build
make[2]: Entering directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_83980.dir/CheckSymbolExists.c.o
/home/giuliobenetti/autobuild/run/instance-0/output-1/host/bin/powerpc-linux-gcc --sysroot=/home/giuliobenetti/autobuild/run/instance-0/output-1/host/powerpc-buildroot-linux-uclibc/sysroot   -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -fvisibility=hidden -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare -Wpedantic   -DNDEBUG   -o CMakeFiles/cmTC_83980.dir/CheckSymbolExists.c.o   -c /home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c
/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c: In function 'main':
/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: error: 'newlocale' undeclared (first use in this function); did you mean 'setlocale'?
   return ((int*)(&newlocale))[argc];
                   ^~~~~~~~~
                   setlocale
/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c:8:19: note: each undeclared identifier is reported only once for each function it appears in
/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c:4:14: warning: parameter 'argc' set but not used [-Wunused-but-set-parameter]
 int main(int argc, char** argv)
          ~~~~^~~~
CMakeFiles/cmTC_83980.dir/build.make:65: recipe for target 'CMakeFiles/cmTC_83980.dir/CheckSymbolExists.c.o' failed
make[2]: *** [CMakeFiles/cmTC_83980.dir/CheckSymbolExists.c.o] Error 1
make[2]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp'
Makefile:121: recipe for target 'cmTC_83980/fast' failed
make[1]: *** [cmTC_83980/fast] Error 2
make[1]: Leaving directory '/home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp'


File /home/giuliobenetti/autobuild/run/instance-0/output-1/build/libiio-0.19/CMakeFiles/CMakeTmp/CheckSymbolExists.c:
/* */
#include <locale.h>

int main(int argc, char** argv)
{
  (void)argv;
#ifndef newlocale
  return ((int*)(&newlocale))[argc];
#else
  (void)argc;
  return 0;
#endif
}