Investigate behavior of `execve` with changed ldlibrary path

[tomuben]

Background

We want to convert the slow wrapper script into a C++ binary, which would be much faster.
For that we need to be sure that changing the environment variable LD_LIBRARY_PATH before replacing the program of the current process using execve has the desired effect.

Acceptance Criteria

The goal is to write two minimal C++ programs:

1. The first loads a shared library which is not in the system LD_LIBRARY_PATH / is linked against this shared library.
2. The second modifies the LD_LIBRARY_PATH and calls the first binrary with execve.

[tkilias]

@tomuben only to avoid missunderstandings

spawning a new process using execve

execve overwrites the current process image and doesn't spawn a new process.

https://man7.org/linux/man-pages/man2/execve.2.html

execve() executes the program referred to by pathname. This
causes the program that is currently being run by the calling
process to be replaced with a new program, with newly initialized
stack, heap, and (initialized and uninitialized) data segments.

[tomuben]

@tkilias adjusted the description. Thanks for pointing out.