Ksh allows variables to contain negative 0 (-0) which breaks equality #74
Description
Because we use =/!= instead of -eq/-ne to compare numbers in conditions, having variables containing -0 breaks this optimization and causes conditions to misfire. The bug doesn't happen when using the variable containing -0 in an arithmetic expansion since -0 is reduced to 0, so it only happens in conditions
See #73 for instructions on how to reproduce the bug.