[clang] [Headers][X86] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow PALIGNR byte shift intrinsics to be used in constexpr (PR #162005)

[Simon Pilgrim via cfe-commits]

RKSimon wrote:

> > @TianYe717 please can you update the patch?
> 
> Ok, I found that there is a problem with this patch and it will be fixed this week

np - please keep an eye on #165513 - as I'm hoping you can use the interp__builtin_ia32_shuffle_generic callback mechanism with the new zero element handling

https://github.com/llvm/llvm-project/pull/162005