[DWARF][NFC] cleanup (mostly leftovers from the implementation of string offsets tables)
Majority of the patch by David Blaikie.

Differential Revision: https://reviews.llvm.org/D53741


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345404 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed