clang/gcc: Add build option FREECAD_WARN_ERROR to force to make warnings into errors

src/Mod/JtReader/App/CMakeLists.txt

@@ -56,6 +56,9 @@ SOURCE_GROUP("Module" FILES ${JtReader_SRCS})
 
 add_library(JtReader SHARED ${JtReader_SRCS} ${JRJT_SRCS} ${JtReader_Scripts})
 target_link_libraries(JtReader ${JtReader_LIBS})
+if (FREECAD_WARN_ERROR)
+    target_compile_warn_error(JtReader)
+endif()
 
 fc_target_copy_resource_flat(JtReader
     ${CMAKE_CURRENT_SOURCE_DIR}