Use malloc/free instead of k_malloc/k_free in operator new/delete
implementation or use libstdc++ implementation when available.
Further updated cpp_synchronization sample to enable minimal libc heap
as virtual destructor requires operator delete which depends on free.
Signed-off-by: Jan Van Winkel <jan.van_winkel@dxplore.eu>
Confirms build (and run) of C++17 applications that make use of STL
containers and other features.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>