These GCs usually did not free very much memory but did consume a lot of CPU. They would on low-powered, low-memory devices often take ~1s, during which time the OS might decide the OOM signal wasn't working and kill us before the compaction can complete and free pages. Instead, only release pooled memory.
Also use more appropriate GCReasons in calls of CollectMost/AllGarbage.
TEST=ci
Bug: b/216333343
Change-Id: Ia56b9ca409410f17d40508c69fb1bc9df0ce4028
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/235300
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Ryan Macnak
81143e16c4