Changes

Add debug info traces

This patch adds a (real) final LTTng 2.8 debug info trace.  Fields
has_build_id and has_debug_link were added after the current debug info
trace was added, so we need a more up to date trace.

It also adds 3 synthetic traces used to test specific cases of debug
info analysis.

- exec: Used to test that a viewer properly handles a process doing an
  exec (forgets all previous mappings).
- two_processes: Used to test that a viewer properly handles debug info
  for two distinct processes.
- buildid_debuglink: Used to test that a viewer properly handles all
  combinations of binaries with/without build id/debug link.

This bumps the project's version to 1.5.0.

Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>