V doesn't free memory when building V for performance reasons.

A compiler is a perfect example of an app where freeing memory is totally fine on exit, by the OS.

Fortunately V is efficient and doesn't result in gigabytes of RAM used when compiling large bases of code (V itself is about 110k loc + 100k of vlib).

Once there are code bases that require gigabytes of RAM, we'll add an option to free it as it goes.