Re: MPS codegen

[Helmut Eller <eller.helmut@gmail.com>]

>> The win would be that no code for copying and mirroring would be needed.
>> One downside would be that the hot and cold section end up in the same
>> pool.
>
> Then I didn't understand what you meant. How would you avoid the
> copying? I don't remember seeing something in the MPS docs by which one
> could let it manage a area of memory the user can allocate or specify.

The idea is simply to do something like dump_mmap_contiguous_heap.
Instead of malloc'ing the contiguous chunk of memory use mps_reserve.
After the pdumper has done the usual relocations call mps_commit.

(It might not work out quite like this because the pdumper wants to
allocate something too early, ie. before the mps_commit. But that's the
basic idea.)

The crucial bit that I'm unsure about is if mps_reserve can be used to
allocate many objects in this way.