[llvm] [DWARFLinker][DWARFLinkerParallel][NFC] Refactor DWARFLinker&DWARFLinkerParallel to have a common library. (PR #74725)

[via llvm-commits]

avl-llvm wrote:

>     2. I see some methods are now virtual when they weren't before and some (String)switch statements have increased in the number of cases they handle. Have you had a chance to double check neither of those is affecting the performance of the linker?

I measured performance impact of this patch and it does not introduce any noticeable change. Anyway, I replaced String switch with an integral switch as integral switch should be faster.


https://github.com/llvm/llvm-project/pull/74725