PeepholeOpt: Fix losing subregister indexes on full copies#161310

arsenm merged 2 commits intomainllvm/llvm-project:mainfrom

users/arsenm/peephole-opt/fix-losing-subreg-index-extract-of-full-copyllvm/llvm-project:users/arsenm/peephole-opt/fix-losing-subreg-index-extract-of-full-copyCopy head branch name to clipboard