8f1a38f07b
Introduce `is_acquirable` isolate property that tracks whether isolate can be entered, avoid a `pool_` check that does not work correctly as isolate being shutdown. BUG=https://github.com/dart-lang/sdk/issues/63515 BUG=https://github.com/dart-lang/sdk/issues/63514 TEST=ci Change-Id: I84577ad082d87ead8cdb9f591fabdf918e2f4bd0 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/509221 Reviewed-by: Slava Egorov <vegorov@google.com>