llvm-project

44061d14 - [Headers][X86] Allow AVX512 masked blend intrinsics to be used in constexpr (#156234)

[Headers][X86] Allow AVX512 masked blend intrinsics to be used in constexpr (#156234) This patch enables AVX-512 masked blend intrinsics to be usable in constant expressions (`constexpr`) across various vector widths (128-bit, 256-bit, 512-bit). It updates the respective Clang headers to include the `__DEFAULT_FN_ATTRS_CONSTEXPR` annotation where applicable, and supplements the change with thorough `TEST_CONSTEXPR` checks in the X86 CodeGen test suite to validate constexpr evaluation. Fixes #155796. --------- Co-authored-by: Simon Pilgrim <llvm-dev@redking.me.uk>