[llvm] [llvm-symbolizer] Recognize AIX big archive (PR #150401)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

Your PR title and description are still inadequate. This PR has _nothing_ to do with llvm-symbolizer recognising the _big_ archive format any more than it does to do with other archive formats. Much more pertinent seems to be:

1. Supporting selecting an archive member by specifying the name in brackets after the archive name.
2. Support for `--default-arch` and architecture suffix for archive member selection.

These two points should be described in the title and description. You can mention that this is primarily for AIX big archives in the description, but it's not limited to those and it has nothing to do with recognising big archives specifically.

https://github.com/llvm/llvm-project/pull/150401