Add debug informations to LoopRegion

[luca-patrignani]

NOTE: this is loop_architecture_pt_3 in disguise. This PR is for the Week 1 milestone for my GSoC project. It adds

• what source line range the source filename belongs to the loop body (for both for and while constructs)
• what source line range defines the condition check (for the while construct)

These informations are stored as DebugInfoProperty in the LoopRegion class.

Needs confirmation

• I created a separate file ( tests/loop_region_code_location_file.py) containing some functions annotated as dace program which are tested by the unit tests. I placed them to avoid messing up the line numbers every time the test file is modified.

[phschaad]

@luca-patrignani It looks like (since the Loop Regions PR was merged into master) this branch will need to be re-based on top of current master to avoid the conflicts. If you have a chance, can you do that? If you don't have time feel free to let me know so I can take care of it - Thanks! :)