[Vanilla Bug] Fix for the "100 unit bug"

[Rampastring]

Description:

If there are more than 100 buildable FootClass-derived object types (whether it's infantry, vehicles or aircraft), the AI will spam the 100th unit type on the list like there's no tomorrow.

Additional Files:

CnCNet ts-patches has code to turn the "100 unit bug" into a "1000 unit bug": https://github.com/CnCNet/ts-patches/blob/master/src/fix_100_unit_bug.asm