[llvm] [X86] Align f128 and i128 to 16 bytes when passing on x86-32 (PR #138092)

[Trevor Gross via llvm-commits]

tgross35 wrote:

@nikic is this something that would make sense to backport? I know ABI changes are typically a no, but this missed the cutoff by only a few days, and f128 is effectively completely broken without it (though i128 of course works fine). It would also be grouped with the windows f128 abi change 5ee1c0b7148571ed9d60e447b66fb0f35de14576.

https://github.com/llvm/llvm-project/pull/138092