[libpng] Apply 893b811 from upstream to fix macro issue

The latest version of Clang changed what macros it predefines on Apple
targets, causing errors about predefined macros in libpng.

This applies
https://github.com/pnggroup/libpng/commit/893b8113f04d408cc6177c6de19c9889a48faa24
from upstream, which fixed the issue.

Bug: 1519899
Change-Id: I98c568083e2784e02c47d611bf957b1373babe0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5237620
Auto-Submit: Hans Wennborg <hans@chromium.org>
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Cr-Commit-Position: refs/heads/main@{#1252638}
NOKEYCHECK=True
GitOrigin-RevId: 66defc14abe47c0494da9faebebfa0a5b6efcf38
2 files changed