internal/trace: use the correct stack for goroutine naming in v2 traces
Currently goroutine names are determined (for v2 traces) by
internal/tracev/2.Event.Stack, but this is wrong in general. For
example, if we end up seeing a transition from GoNotExist->GoRunnable
(goroutine creation) then we're taking the stack from the creator, not
the created goroutine (which is what we're naming at that point).
Use the StateTransition.Stack instead. This is always the correct one to
use because we're always naming the goroutine that the state transition
is for.
Change-Id: I3fc7c8e4f85dfee3802d666c0c091b6953c7d6cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/544317
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com>