Add virtmemFindAliasMemory to virtmem APIs

[DCNick3]

No description provided.

[fincs]

This won't work as intended, because _memregionFindRandom explicitly checks that the returned address isn't within the Alias region.

What is the intended use case of this PR? I suppose it is related to switchbrew/nx-hbloader#35?

[DCNick3]

Didn't notice that, sorry.

Yes, it is related =)

My intended use is as follows: I want to reserve a large region of virtual address space (probably 4 GiB) and later map physical memory to parts of it. This would allow to write efficient emulation for 32-bit systems supporting virtual memory by simply adding the reserved region base to emulated system virtual address. This is how qemu user emulation basically works.

I want it to emulate (small subset of) windows 95 APIs to run Heroes of Might and Magic III on hos.

[fincs]

I see; that is indeed quite an interesting project.

We haven't tackled support for PhysicalMemory SVCs yet; but it is indeed in the cards.

[fincs]

I'm closing this PR. However I'm opening an issue that is specifically about the future support for PhysicalMemory SVCs: #503