Add align requirement in _mm_stream_si32 and _mm_stream_si64

[yilin0518]

Update alignment documentation for _mm_stream_si32 and _mm_stream_si64

The documentation for _mm_stream_si32 and _mm_stream_si64 previously described the target as a generic memory location, but did not mention the required alignment of the memory address.

These intrinsics imply that the destination memory should be naturally aligned: 4 bytes for _mm_stream_si32 and 8 bytes for _mm_stream_si64.

Similar store intrinsics(_mm_stream_si128, _mm_stream_si256, _mm512_stream_si512) already document their alignment requirements, and the existing tests for these APIs also use properly aligned memory. This PR updates the documentation to make the alignment requirements explicit and consistent with the surrounding APIs.

This is a documentation-only change.

[rustbot]

Thanks for the pull request, and welcome! The Rust Project is excited to review your changes, and you should hear from @davidtwco (or someone else) some time within the next two weeks.

Why was this reviewer chosen?

The reviewer was selected based on:

• Owners of files modified in this PR: @Amanieu, @adamgemmell, @davidtwco, @folkertdev, @sayantn
• @Amanieu, @adamgemmell, @davidtwco, @folkertdev, @sayantn expanded to Amanieu, adamgemmell, davidtwco, folkertdev, sayantn
• Random selection from Amanieu, adamgemmell, davidtwco, folkertdev, sayantn

[yilin0518]

The CI failed in some stages, but I think the changes I made should not produce any CI fail. I think there are some mistakes when the CI runs. Could you review about the CI result? Thank you for your help!

[folkertdev]

cc @sayantn apparently icx fails to install somehow?