base64-ng 1.3.4

[eldryoth]

base64-ng 1.3.4

1.3.4 is a big-endian evidence and release-governance patch for the
base64-ng crate family.

Highlights

• Added required s390x-unknown-linux-gnu QEMU user-mode evidence for
  big-endian functional correctness and scalar/fallback runtime behavior.
• Added release-gated checks proving stable Rust still gates s390x and
  PowerPC64 vector intrinsics behind unstable stdarch_* features on the
  active release toolchain.
• Documented that big-endian acceleration is deliberately not admitted in this
  release. QEMU evidence is correctness/fallback evidence only, not hardware
  performance, timing, side-channel, register-retention, or production-CPU
  equivalence evidence.
• Improved the optional PowerPC64 QEMU path with an early glibc sysroot
  preflight, so maintainers get a clear missing-sysroot error when only the
  cross compiler is installed.
• Synchronized all workspace crate package versions to 1.3.4.

Notes

The admitted SIMD acceleration scope is unchanged from 1.3.3. Big-endian
targets remain scalar/fallback-only until stable Rust exposes reviewed
intrinsic paths or the project accepts a separate assembly-backed backend
review with real hardware evidence.

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This discussion was created from the release base64-ng 1.3.4.