Update libpng to 1.6.42

3rdparty/libpng/CMakeLists.txt

@@ -4,11 +4,9 @@ if (NOT USE_SYSTEM_LIBPNG)
 	# We use libpng's static library and don't need to build the shared library and run the tests
 	set(PNG_SHARED OFF CACHE BOOL "Build shared lib")
 	set(PNG_TESTS OFF CACHE BOOL "Build libpng tests")
-	set(PNG_BUILD_ZLIB ON CACHE BOOL "ZLIB is already build or package is found")
 	set(SKIP_INSTALL_ALL ON)
 	add_subdirectory(libpng EXCLUDE_FROM_ALL)
 	target_include_directories(png_static INTERFACE "${libpng_BINARY_DIR}" "${libpng_SOURCE_DIR}")
-	target_link_libraries(png_static 3rdparty::zlib)
 
 	set(LIBPNG_TARGET png_static PARENT_SCOPE)
 else()

3rdparty/zlib/CMakeLists.txt

@@ -1,10 +1,9 @@
 if (USE_SYSTEM_ZLIB)
 	message(STATUS "RPCS3: Using system ZLIB")
-	find_package(ZLIB QUIET)
+	find_package(ZLIB QUIET REQUIRED)
 
 	add_library(3rdparty_zlib INTERFACE)
-	target_link_libraries(3rdparty_zlib INTERFACE ${ZLIB_LIBRARIES})
-	target_include_directories(3rdparty_zlib INTERFACE ${ZLIB_INCLUDE_DIRS})
+	target_link_libraries(3rdparty_zlib INTERFACE ZLIB::ZLIB)
 	target_compile_definitions(3rdparty_zlib INTERFACE -DZLIB_CONST=1)
 else()
 	message(STATUS "RPCS3: Using builtin ZLIB")
@@ -15,4 +14,6 @@ else()
 	target_link_libraries(3rdparty_zlib INTERFACE zlibstatic)
 	target_include_directories(3rdparty_zlib INTERFACE zlib ${CMAKE_CURRENT_BINARY_DIR}/zlib)
 	target_compile_definitions(3rdparty_zlib INTERFACE -DZLIB_CONST=1)
+
+	set(ZLIB_ROOT ${CMAKE_CURRENT_BINARY_DIR}/zlib PARENT_SCOPE)
 endif()