[PowerPC] Replace vspltisw+vadduwm instructions with xxleqv+vsubuwm for adding the vector {1, 1, 1, 1}#160882

Himadhith wants to merge 4 commits intollvm:mainllvm/llvm-project:mainfrom

Himadhith:himadhith/xxleqv_vecHimadhith/llvm-project:himadhith/xxleqv_vecCopy head branch name to clipboard