[clang] [X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 mask predicate intrinsics to be used in constexpr (PR #165054)

[Simon Pilgrim via cfe-commits]

https://github.com/RKSimon requested changes to this pull request.

Still missing most of header changes + corresponding test coverage

https://github.com/llvm/llvm-project/pull/165054