[llvm] [llvm][RISCV] Implement Zilsd load/store pair optimization (PR #158640)

[Djordje Todorovic via llvm-commits]

================
@@ -52,6 +52,7 @@ add_llvm_target(RISCVCodeGen
   RISCVLandingPadSetup.cpp
   RISCVLateBranchOpt.cpp
   RISCVLoadStoreOptimizer.cpp
+  RISCVZilsdOptimizer.cpp
----------------
djtodoro wrote:

alphabetize

https://github.com/llvm/llvm-project/pull/158640