clang-analyzer_unity warnings for Arx in branch master

• core.DivideZero (1 | =)
• unix.Malloc (2 | =)
• core.UndefinedBinaryOperatorResult (4 | =)
• core.uninitialized.Assign (4 | =)
• deadcode.DeadStores (4 | =)
• core.CallAndMessage (7 | =)