runtime, testing/synctest: breaking bubble isolation with Cond is fatal
sync.Cond.Wait is durably blocking. Waking a goroutine out of Cond.Wait
from outside its bubble panics.
Make this panic a fatal panic, since it leaves the notifyList in an
inconsistent state. We could do some work to make this a recoverable
panic, but the complexity doesn't seem worth the outcome.
For #67434
Change-Id: I88874c1519c2e5c0063175297a9b120cedabcd07
Reviewed-on: https://go-review.googlesource.com/c/go/+/675617
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Damien Neil <dneil@google.com>