Update PNG library to avoid more -Wundef warnings in MinGW build

Define symbols used in MIPS/PPC code which are also tested using "#if
PNG_FOO > 0" as 0 instead of leaving them undefined.
This commit is contained in:
Vadim Zeitlin
2020-05-03 02:57:58 +02:00
parent fc08ce94a5
commit 43bdadda0d

Submodule src/png updated: f1ecc2c50d...46b17e804b