aarch64-linux-gnu-gcc: error trying to exec 'cc1plus' : execvp: No such file or directory
Solution 1:
cc1plus is the internal front end program name for the Gnu Compiler Collection's C++ compiler. It's being called in this case because gcc has detected that test.cpp is a C++ file rather than a C file.
You would get it by installing the corresponding g++ package for the C compiler that you are using. For the aarch64-linux-gnu-gcc cross compiler, that would be g++-aarch64-linux-gnu I think.
You should then use aarch64-linux-gnu-g++ to compile your .cpp sources.