Fix issue where a new GC could be started during a GC

[Bug #21548]

In lazy sweeping, if we need to allocate an object in a heap where we
weren't able to free any slots, but we also either have empty pages or
could allocate new pages, then we want to preemptively claim a page
because it's possible that sweeping another heap will call gc_sweep_finish_heap,
which may use up all of the empty/allocatable pages. If other heaps are
not finished sweeping then we do not finish this GC and we will end up
triggering a new GC cycle during this GC phase.

0 files changed, 0 insertions, 0 deletions