clang-analyzer_unity warnings for Arx in branch master

• core.uninitialized.UndefReturn (1 | =)
• unix.Errno (1 | =)
• core.NullDereference (2 | =)
• core.UndefinedBinaryOperatorResult (2 | =)
• unix.Malloc (2 | =)
• unix.StdCLibraryFunctions (2 | =)
• core.uninitialized.Assign (4 | =)
• deadcode.DeadStores (4 | =)
• core.CallAndMessage (6 | =)