[llvm] [LoongArch][Disassembler] Add symbolic operands for decoded immediates (PR #217971)

[Lu Weining via llvm-commits]

SixWeining wrote:

Thank you very much for your contribution. I have a small note regarding the submission process for Pull Requests: the LLVM community only allows squash commits (i.e., multiple commits within the same PR will be squashed into one before merging). This means that if you prefer to have your changes merged as separate commits, you will need to submit each commit as an individual PR.  If you have commit access to the repository, you can try using `spr` or `GitHub Stacked PRs`. See #218597 for example. Otherwise, you will need to create separate PRs and manually rebase subsequent PRs after the preceding ones have been merged.

https://github.com/llvm/llvm-project/pull/217971