[Headers][X86] Add constexpr support for some AVX512 int to f16 intrinsics. (#159231)
Added constexpr to the remaining intrinsics:
_mm256_cvtepu16_ph
_mm256_mask_cvtepu16_ph
_mm256_maskz_cvtepu16_ph
_mm256_cvtepi32_ph
_mm256_mask_cvtepi32_ph
_mm256_maskz_cvtepi32_ph
_mm256_cvtepu32_ph
_mm256_mask_cvtepu32_ph
_mm256_maskz_cvtepu32_ph
Last part fixing #155798