clang-analyzer_unity warnings for Arx in branch 1.2.1

• core.uninitialized.Branch (1)
• unix.Errno (1)
• unix.Malloc (1)
• core.UndefinedBinaryOperatorResult (2)
• unix.StdCLibraryFunctions (2)
• core.uninitialized.Assign (3)
• -Wnan-infinity-disabled [docs] (4)
• deadcode.DeadStores (5)
• core.CallAndMessage (6)