I know that OCaml, Haskell, the JVM and Microsoft .NET do it (I think Mono does, too, but am not positive). And I know for a fact that OCaml and the JVM inline

I know that OCaml, Haskell, the JVM and Microsoft .NET do it (I think Mono does, too, but am not positive). And I know for a fact that OCaml and the JVM inline allocations and optimize multiple allocations that are close together (e.g. increasing the allocation pointer only once even if you allocate a pair of objects). It's fairly common and needed for modern functional languages, as they can go through a lot of temporary objects when programming in a purely functional style.