Spurious test failure of large_high_align on x64 MSVC

[jonas-schievink]

The test allocates 1 MiB aligned to 1 MiB, so it shouldn't really hit OOM (I think). Yet this log indicates that the allocation failed (by returning a NULL pointer).

All other builds have passed, so this might even be specific to x86_64-pc-windows-msvc.

[jonas-schievink]

I've reproduced this for both small_high_align and large_high_align under wine:

running 6 tests
test tests::align_less_than_sizeof_usize ... ok
test tests::align_not_power_of_two ... ok
test tests::align_zero ... ok
test tests::large_high_align ... ok
test tests::small_high_align ... FAILED
test tests::small_low_align ... ok

failures:

---- tests::small_high_align stdout ----
	thread 'tests::small_high_align' panicked at 'assertion failed: !ptr.is_null()', src/lib.rs:148

running 6 tests
test tests::align_less_than_sizeof_usize ... ok
test tests::align_not_power_of_two ... ok
test tests::align_zero ... ok
test tests::large_high_align ... FAILED
test tests::small_high_align ... ok
test tests::small_low_align ... ok

failures:

---- tests::large_high_align stdout ----
	thread 'tests::large_high_align' panicked at 'assertion failed: !ptr.is_null()', src/lib.rs:157