[DWARF] Move a couple of member functions to the DWARFUnit baseclass. NFC.

Reviewer: dblaikie

Differential revision: https://reviews.llvm.org/D34765



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306771 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed