[ObjectYAML] Support for DWARF debug_info section

This patch adds support for YAML<->DWARF for debug_info sections.

This re-lands r290147, after fixing the issue that caused bots to fail (thank you UBSan!).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290204 91177308-0d34-0410-b5e6-96231b3b80d8
11 files changed