[clang] [llvm] Reapply "[AArch64][SVE] Improve fixed-length addressing modes. (#130263)" (PR #130625)

[Ricardo Jesus via cfe-commits]

rj-jesus wrote:

Thank you very much for the explanation, @paulwalker-arm - that makes a lot of sense! I'll try your suggestion tomorrow. I'll let you know how it goes. :) 

https://github.com/llvm/llvm-project/pull/130625