[zlib] Only create needed vectors for crc_fold_512

The original x86 specific folding CRC code contributed back in 2015
used a macro pair (CRC_LOAD/CRC_SAVE) to load and store data vectors that is
reused along the code.

Modern compilers (e.g. VS2022) will complain about unused code past the return
in crc_fold_512to32 which only needs the first 4 sets of vectors
(xmm_crc0 .. xmm_crc3) and this patch fixes the issue.

For reference, see warning C4702:
https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-4-c4702?view=msvc-170

Bug: 1426252
Change-Id: I9636a7705f7f7c869b5bcfc4f7d35795614c7d23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4409500
Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Adenilson Cavalcanti <cavalcantii@chromium.org>
Reviewed-by: Chris Blume <cblume@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1128743}
NOKEYCHECK=True
GitOrigin-RevId: 955a57f0b03d7a2b6266d535f9e6ba03ba26a340
1 file changed