Add NMAX_ALIGNED32 and use it in NEON adler32

Define NMAX_ALIGNED32 as NMAX rounded down to a multiple of 32 (5536)
and use it in the NEON adler32 implementation to ensure that src stays
32-byte aligned throughout the main SIMD loop. Previously, NMAX (5552)
is not a multiple of 32, so after the alignment preamble the first
iteration could process a non-32-aligned number of bytes, causing src
to lose 32-byte alignment for all subsequent iterations.

The first iteration's budget is rounded down with ALIGN_DOWN after
subtracting align_diff, ensuring k is always a multiple of 32.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions