[X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 mask predicate intrinsics to be used in constexpr

[RKSimon]

These predicate intrinsics seem to have been missed, but can easily be implemented, along with suitable test coverage:

_mm512_kmov

_cvtmask8_u32 _cvtmask16_u32 _cvtmask32_u32 _cvtmask64_u64
_cvtu32_mask8 _cvtu32_mask32 _cvtu64_mask64

_mm512_kunpackb _mm512_kunpackw _mm512_kunpackd

_mm_movepi8_mask _mm256_movepi8_mask _mm512_movepi8_mask
_mm_movepi16_mask _mm256_movepi16_mask _mm512_movepi16_mask
_mm_movepi32_mask _mm256_movepi32_mask _mm512_movepi32_mask
_mm_movepi64_mask _mm256_movepi64_mask _mm512_movepi64_mask

_mm_movm_epi8 _mm256_movm_epi8 _mm512_movm_epi8
_mm_movm_epi16 _mm256_movm_epi16 _mm512_movm_epi16
_mm_movm_epi32 _mm256_movm_epi32 _mm512_movm_epi32
_mm_movm_epi64 _mm256_movm_epi64 _mm512_movm_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:

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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)

These predicate intrinsics seem to have been missed, but can easily be implemented, along with suitable test coverage: ``` _cvtmask8_u32 _cvtmask16_u32 _cvtmask32_u32 _cvtmask64_u64 _cvtu32_mask8 _cvtu32_mask32 _cvtu64_mask64

_mm512_kunpackb _mm512_kunpackw _mm512_kunpackd

_mm_movepi8_mask _mm256_movepi8_mask _mm512_movepi8_mask
_mm_movepi16_mask _mm256_movepi16_mask _mm512_movepi16_mask
_mm_movepi32_mask _mm256_movepi32_mask _mm512_movepi32_mask
_mm_movepi64_mask _mm256_movepi64_mask _mm512_movepi64_mask

_mm_movm_epi8 _mm256_movm_epi8 _mm512_movm_epi8
_mm_movm_epi16 _mm256_movm_epi16 _mm512_movm_epi16
_mm_movm_epi32 _mm256_movm_epi32 _mm512_movm_epi32
_mm_movm_epi64 _mm256_movm_epi64 _mm512_movm_epi64

</details>

[llvmbot]

@llvm/issue-subscribers-backend-x86

Author: Simon Pilgrim (RKSimon)

These predicate intrinsics seem to have been missed, but can easily be implemented, along with suitable test coverage: ``` _cvtmask8_u32 _cvtmask16_u32 _cvtmask32_u32 _cvtmask64_u64 _cvtu32_mask8 _cvtu32_mask32 _cvtu64_mask64

_mm512_kunpackb _mm512_kunpackw _mm512_kunpackd

_mm_movepi8_mask _mm256_movepi8_mask _mm512_movepi8_mask
_mm_movepi16_mask _mm256_movepi16_mask _mm512_movepi16_mask
_mm_movepi32_mask _mm256_movepi32_mask _mm512_movepi32_mask
_mm_movepi64_mask _mm256_movepi64_mask _mm512_movepi64_mask

_mm_movm_epi8 _mm256_movm_epi8 _mm512_movm_epi8
_mm_movm_epi16 _mm256_movm_epi16 _mm512_movm_epi16
_mm_movm_epi32 _mm256_movm_epi32 _mm512_movm_epi32
_mm_movm_epi64 _mm256_movm_epi64 _mm512_movm_epi64

</details>

[sskzakaria]

@RKSimon Hi could I work on this?