[lttng-dev] [RFC lttng-ust v3] Add memory size, build id, and debug link info to statedump and dl

[Antoine Busque]

This patch set implements a minimal ELF parser to add extra
information necessary for callsite analysis to the statedump and dl
helper. Please pull from
https://github.com/abusque/lttng-ust/tree/elf-info-v3

Also included are unit tests covering x86, x86_64, armeb, and aarch_64
targets.

Changes from version 1:

- More uniform and thorough error handling (i.e. always return -1 on failure,
  0 on success)
- Make distinction between information not found in ELF file and
  actual errors (found status is returned through an out parameter on
  function success)
- Functions have no side-effects on failure
- Add more cases to the unit tests for better coverage
- Minor style issues

Changes from version 1:

- Fixed coding style issues
- More rigorous error handling
- Field reordering in tracepoints and structs for optimization

Regards,
Antoine Busque