P.S.

I should add that the JVM (and Go) also infers lifetime for non-escaping objects and "allocates" them in registers (which can spill to the stack; i.e. `new X()` in Java may or may not actually allocate anything in the heap). The point is that different GCs involve compiler-inferred lifetimes to varying degrees, and if there's a clear line between them is less the role of the compiler (although that's certainly an interesting detail) and more whether they generally optimise for footprint (immediate `free` when the object becomes unreachable) or throughput (compaction in a moving-tracing collector, with no notion of `free` at all).

There are also big differences between moving and non-moving tracing collectors (Go's concurrent mark & sweep and Java's now removed CMS collector). A CMS collector still has concepts that resemble malloc and free (such as free lists), but a moving one doesn't.