iOS appears not to allow any single virtual memory allocation to exceed ~700MB.
iOS appears to limit the total amount of allocated virtual memory to amount of physical memory available, even virtual memory that is reserved by not committed.
So instead of trying to allocate the full 4GB region for compressed pointer, allocate the largest power-of-two that succeeds, and speculate that further allocations to into the same 4GB region.
TEST=none
Change-Id: Ib45f7ece59e1adb96d175ae861b984c0c6737549
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210640
Reviewed-by: Siva Annamalai <asiva@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Ryan Macnak