[llvm] [RISCV]Add support for resolving encoding conflicts among vendor specific CSRs (PR #96174)

[Garvit Gupta via llvm-commits]

quic-garvgupt wrote:

Hi, @wangpc-pp , @apazos, @asb, @topperc , can you please review this PR? Thanks

Re: for creating separate PR for changes in searchable Tables @wangpc-pp 
>> I understand that the changes will affect all targets, however before sending this PR to more broader set of reviewers, I wanted to know the comments from the reviewers of RISCV community because the framework here is to resolve encoding conflicts among CSRs, which as per my understanding in unique to RISCV. If and when this change is approved for RISCV, I will push it to a different PR with a broad set of reviewers. 

https://github.com/llvm/llvm-project/pull/96174