Test system allocators for >2 GiB on 32-bit success

[MaulingMonkey]

Rust APIs guard against isize::MAX allocs, check how easy it is to break that without said checks.

• std::ffi::CStr::from_ptr was given as a problematic example API
• Consider using VMMap (Sysinternals) on a binary
• Consider utilizing crates/no-std/examples/trivial.rs as the demo binary
• _HEAP_MAXREQ does imply terrible things
• Verify with /LARGEADDRESSAWARE
• LegionMammal978 was only able to achieve an empirical maximum hole of 0x7fe5e000 bytes (discord)