[llvm] [RelLookupTableConverter] Enable relative lookup tables on Arm. (PR #77910)

[Simon Tatham via llvm-commits]

statham-arm wrote:

@gulfemsavrun , I'd like your opinion because it looks as if you added this pass originally, but I couldn't find any comments explaining the reason for the restriction to 64-bit pointers. Is there something I've missed about why it won't work to do this for 32-bit?

https://github.com/llvm/llvm-project/pull/77910