[llvm] [DWARF] Add accessor for NameIndex Offsets field. (PR #88783)

[Fangrui Song via llvm-commits]

MaskRay wrote:

LGTM. Perhaps the commit message (first comment) can be clarified to say that this will be used by `ld.lld --debug-names`?

BTW, most commit messages omit a full stop for the subject line.

https://github.com/llvm/llvm-project/pull/88783