[llvm] Allow the dumping of .dwo files contents to show up when dumping an e… (PR #66726)

[Greg Clayton via llvm-commits]

clayborg wrote:

Everything should be fixed. Now if you specify `--dwo` along with `--name`, it will search the .dwo files for the name. If `--dwo` isn't specified, then it will search the skeleton compile unit only.

Same thing for lookups. This allows you to search the skeleton compile unit for an address, or the dwo if you specify `--dwo`. 

Added tests for everything.

https://github.com/llvm/llvm-project/pull/66726