TotLM is not IWD: EE for GAME_IS
Credit Nicolás Clotta
Auto-initialise a variable in ADD_AREA_REGION

The old code was not using the variable (bug), but the new code does.
There are in-the-wild uses of the macro that do not initialise the
variable and we need to cover that scenario.
Fix structure-detail bug in fj_are_structure