Prevents applications that accidentally attempt to allocate massive amounts of memory from getting OOM killed
(An example of such an application is EverQuest's DX11 beta, which has some corrupted asset files that result in it trying to allocate ~18TB of memory)
BTW, is it okay to have a test that's likely to get OOM killed on a failing implementation? If not, any recommendations on how else to test this?
-- v2: ntdll/tests: Add test for reserving massive amounts of memory.