Build fails on i386: could not find `x86_64` in `arch`

```
error[E0432]: unresolved import `core::arch::x86_64`
--> /wrkdirs/usr/ports/databases/iceberg-rust/work/iceberg-rust-0.9.1/cargo-crates/sonic-simd-0.1.3/src/sse2.rs:2:11
|
2 | arch::x86_64::*,
| ^^^^^^ could not find `x86_64` in `arch`
```

[log](https://pkg-status.freebsd.org/beefy19/data/144i386-quarterly/9d25c757e0f7/logs/apache-iceberg-rust-0.9.1.log)

Start with the linked FreeBSD i386 build log and cargo-crates/sonic-simd-0.1.3/src/sse2.rs, where the unresolved core::arch::x86_64 import is reported. Determine the appropriate i386 build behavior from the surrounding crate configuration. Done means the apache-iceberg-rust build completes on i386 without this unresolved import.

Written by the indexing model from the issue text.