Suppress numerous libz warnings (#6709)

* Suppress numerous libz warnings

zlib will fix this issue later (see madler/zlib#633).
For now we will just turn off the warning.

* Fix Windows build

third_party/libassimp/tnt/CMakeLists.txt

@@ -278,6 +278,7 @@ if(NOT MSVC)
         PRIVATE -Wno-unused-const-variable
         PRIVATE -Wno-unused-private-field
         PRIVATE -Wno-unused-variable
+        PRIVATE -Wno-deprecated-non-prototype # See https://github.com/madler/zlib/issues/633
     )
 else()
     target_compile_options(${TARGET} PRIVATE /bigobj)

third_party/libz/tnt/CMakeLists.txt

@@ -46,16 +46,17 @@ set(SRCS
     ${SRC_DIR}/zutil.c
 )
 
+# we're building a library
+add_library(${TARGET} STATIC ${PRIVATE_HDRS} ${PUBLIC_HDRS} ${SRCS})
+
 if (NOT MSVC)
-    add_definitions(
-        -Wno-implicit-function-declaration
-        -Wno-shift-negative-value
+    target_compile_options(${TARGET}
+        PRIVATE -Wno-implicit-function-declaration
+        PRIVATE -Wno-shift-negative-value
+        PRIVATE -Wno-deprecated-non-prototype # See https://github.com/madler/zlib/issues/633
     )
 endif()
 
-# we're building a library
-add_library(${TARGET} STATIC ${PRIVATE_HDRS} ${PUBLIC_HDRS} ${SRCS})
-
 # specify where the public headers of this library are
 target_include_directories (${TARGET} PUBLIC ${PUBLIC_HDR_DIR})
 set_target_properties(${TARGET} PROPERTIES FOLDER ThirdParty)