In Delphi that afaik depends on version. Originally it was in classes, later it moved to contnrs (D6+) afaik. In comparisons with Delphi always list the exact code and the used version (and double check that it is still the case, a mistake is easily made)
in FPC/Lazarus the plain tobjectlist is also in contnrs. If you importat contnrs before generics.collections in the uses list you can refer to the non generic one as
x:=contnrs.tobjectlist<contnrs>.create