[RISCV] Propagate SDNode flags when combining `(fmul (fneg X), ...)`#169460

mshockwave merged 4 commits intollvm:mainllvm/llvm-project:mainfrom

mshockwave:patch/riscv/fix-fma-combine-contractmshockwave/llvm-project:patch/riscv/fix-fma-combine-contractCopy head branch name to clipboard