[zlib] Re-sync with zlib 1.2.12, patch 8 of N

Missed this change in patchset 5.

Ported:
- Don't compute check value for raw inflate if asked to validate
- Handle case where inflateSync used when header never processed

Bug: 1032721
Change-Id: Idbc1fa4cd36a18ab5e775469406984ac2ebb27eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3575094


Reviewed-by: Chris Blume <cblume@chromium.org>
Commit-Queue: Adenilson Cavalcanti <cavalcantii@chromium.org>
Cr-Commit-Position: refs/heads/main@{#989610}
NOKEYCHECK=True
GitOrigin-RevId: 3d72651da0f066f6e9b16381cf59abe2f1e0c2e5