[PATCH] Add DWARF support to rtemstoolkit and use it in covoar

[Chris Johns]

Hi

The patch series adds a DWARF framework to the rtemstoolkit to access the
source file and line given an address in an executable. This allows
us to remove exec'ing addr2line.

The patches build and the source line details are loaded from the DWARF
debug info. I however do not have any coverage data to check the change
cleanly replaces the existing addr2line calls.

If someone can run the existing covoar and then this build of covoar and
confirm the source files and lines match. If there are issues please let
me know.

Chris