[llvm] [X86] Fix swapped VPTERNLOG231_imm8/VPTERNLOG312_imm8 SDNodeXForm bodies (PR #209782)

[via llvm-commits]

AntonyCJ30 wrote:

These failures are unrelated to this PR:
- Clang.AST/ByteCode/virtual-bases.cpp (Clang AST)
- LLVM.CodeGen/Mips/msa/f16-llvm-ir.ll (MIPS backend)

This PR only touches X86 VPTERNLOG and all relevant tests passed.

https://github.com/llvm/llvm-project/pull/209782