[obj2yaml] Refactor and abstract dwarf2yaml

This makes the dwarf2yaml code separated and reusable allowing ELF and COFF to share implementations with MachO.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288986 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed