[llvm] [llvm-symbolizer] Have --obj participate in markup resolution (PR #183444)

[Joshua Seaton via llvm-commits]

joshuaseaton wrote:

> The PR description could use a more specific mention that this is primarily intended to help the "markup filter" feature. This is something that was added relatively recently to `llvm-symbolizer`, so it's worth calling out.

Done

https://github.com/llvm/llvm-project/pull/183444