Add a first draft for automatic privatization of global variables for smpi.

Add a first draft for automatic privatization of global variables for smpi.
Activated with --cfg="smpi/privatize_global_variables":yes
This will read executable (using objdump for now), find addresses of .data and .bss segments and for each process (even 0 for now) copy all this data inside an mmaped zone
Each time the simulated process executes some code, or each time we copy data from these zones, the data segment is mmaped from the one of the corresponding process.