[llvm.py] Implement interface to object files

It is now possible to load object files and scan over sections, symbols,
and relocations! Includes test code with partial coverage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152482 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed