Add constructor for DSOAndOffset

Initialize the fields. Add a unit test to make sure dso_info() access
works.

BUG=none
TEST=unit tests pass

Change-Id: I08b45f5c38a143174ea7bd331329c3682ddffb4a
Signed-off-by: Simon Que <[email protected]>
Reviewed-on: https://chromium-review.googlesource.com/181410
Reviewed-by: Ahmad Sharif <[email protected]>
2 files changed