[PATCH] [dwarfdump] Implement extraction of file information referenced in .debug_info.

[Frederic Riss]

Sorry for the spam. I'm still learning to use arcanist, and I must say at this point it's more a burden that a help... This latest revision is the result of a small series of 3 commits that should be easy enough to distinguish. They aren't really intermingled except for the test updates.
The first just prints the line numbers in decimal and updates the tests.
The second moves some static helpers of DWARFContext.cpp into equivalent methods of LineTable. There should be no functional change though.
The third one uses the newly exposed method to find and print full names for files referenced by DW_AT_(decl|call)_file.

http://reviews.llvm.org/D5192