[Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 conflict intrinsics to be used in constexpr

[RKSimon]

_mm_conflict_epi32 _mm_mask_conflict_epi32 _mm_maskz_conflict_epi32 
_mm_conflict_epi64 _mm_mask_conflict_epi64 _mm_maskz_conflict_epi64 
_mm256_conflict_epi32 _mm256_mask_conflict_epi32 _mm256_maskz_conflict_epi32 
_mm256_conflict_epi64 _mm256_mask_conflict_epi64 _mm256_maskz_conflict_epi64
_mm512_conflict_epi32 _mm512_mask_conflict_epi32 _mm512_maskz_conflict_epi32 
_mm512_conflict_epi64 _mm512_mask_conflict_epi64 _mm512_maskz_conflict_epi64

[llvmbot]

@llvm/issue-subscribers-backend-x86

Author: Simon Pilgrim (RKSimon)

``` _mm_conflict_epi32 _mm_mask_conflict_epi32 _mm_maskz_conflict_epi32 _mm_conflict_epi64 _mm_mask_conflict_epi64 _mm_maskz_conflict_epi64 _mm256_conflict_epi32 _mm256_mask_conflict_epi32 _mm256_maskz_conflict_epi32 _mm256_conflict_epi64 _mm256_mask_conflict_epi64 _mm256_maskz_conflict_epi64 _mm512_conflict_epi32 _mm512_mask_conflict_epi32 _mm512_maskz_conflict_epi32 _mm512_conflict_epi64 _mm512_mask_conflict_epi64 _mm512_maskz_conflict_epi64 ```

[llvmbot]

Hi!

This issue may be a good introductory issue for people new to working on LLVM. If you would like to work on this issue, your first steps are:

1. Check that no other contributor is working on this issue. If someone is assigned to the issue or claimed to be working on it, ping the person. After one week without a response, the assignee may be changed.
2. Leave a comment indicating that you are working on the issue, or just create a pull request after following the steps below. Mention this issue in the description of the pull request.
3. Fix the issue locally.
4. Run the test suite locally. Remember that the subdirectories under test/ create fine-grained testing targets, so you can e.g. use make check-clang-ast to only run Clang's AST tests.
5. Create a Git commit.
6. Run git clang-format HEAD~1 to format your changes.
7. Open a pull request to the upstream repository on GitHub. Detailed instructions can be found in GitHub's documentation. Mention this issue in the description of the pull request.

If you have any further questions about this issue, don't hesitate to ask via a comment in the thread below.

[llvmbot]

@llvm/issue-subscribers-good-first-issue

Author: Simon Pilgrim (RKSimon)

``` _mm_conflict_epi32 _mm_mask_conflict_epi32 _mm_maskz_conflict_epi32 _mm_conflict_epi64 _mm_mask_conflict_epi64 _mm_maskz_conflict_epi64 _mm256_conflict_epi32 _mm256_mask_conflict_epi32 _mm256_maskz_conflict_epi32 _mm256_conflict_epi64 _mm256_mask_conflict_epi64 _mm256_maskz_conflict_epi64 _mm512_conflict_epi32 _mm512_mask_conflict_epi32 _mm512_maskz_conflict_epi32 _mm512_conflict_epi64 _mm512_mask_conflict_epi64 _mm512_maskz_conflict_epi64 ```

[chaitanyav]

@RKSimon can i work on this?.

[RKSimon]

Have you experience with the conflict instructions and do you have a suitable avx512 machine to test them on?

[chaitanyav]

i have not worked with conflict instructions, i do have an amd ryzen 9 to test.