[clang] [llvm] [PowerPC] Update data layout aligment of i128 to 16 (PR #118004)

[Amy Kwan via cfe-commits]

https://github.com/amy-kwan commented:

For the most part, I think it looks good but I just have one comment about a change that (I think) doesn't need to happen.

https://github.com/llvm/llvm-project/pull/118004