DWARF-4/CFA Support

[Theldus]

Description

At the moment, PBD relies on DWARF-2/Location lists to find the appropriate variable location (whether local or global). Although not an issue, this requires the user to building the target code with -gdwarf-2 (instead of only -g) flag since GCC/CLang no longer uses DWARF-2 as default.

Supporting DWARF version 4 would be great since from this version onwards, compilers started to use CFA (Call Frame Information) as the default way to indicate variable locations and just requires the user to pass -g to emit debugging symbols.

Useful resources:

• https://stackoverflow.com/questions/33071545/what-do-i-do-with-dw-op-call-frame-cfa
• https://stackoverflow.com/questions/56204213/how-to-parse-dw-op-call-frame-cfa