Fix warning related to unused-function.

Signed-off-by: Jackie9527 <80555200+Jackie9527@users.noreply.github.com>

code/CMakeLists.txt

@@ -1198,7 +1198,6 @@ IF (ASSIMP_WARNINGS_AS_ERRORS)
 
     IF(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
       TARGET_COMPILE_OPTIONS(assimp PRIVATE -Wall -Werror
-        -Wno-unused-function
         -Wno-microsoft-enum-value
         -Wno-switch-enum
         -Wno-covered-switch-default

code/Common/StbCommon.h

@@ -48,6 +48,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #pragma GCC diagnostic ignored "-Wunused-function"
 #endif
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-function"
+#endif
+
 #ifndef STB_USE_HUNTER
 /*  Use prefixed names for the symbols from stb_image as it is a very commonly embedded library.
     Including vanilla stb_image symbols causes duplicate symbol problems if assimp is linked
@@ -114,3 +119,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #pragma GCC diagnostic pop
 #endif
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif