reflect: use runtime.AddCleanup instead of runtime.SetFinalizer
Replace a usage of runtime.SetFinalizer with runtime.AddCleanup in
the TestCallReturnsEmpty test. There is an additional use of
SetFinalizer in the reflect package which depends on object
resurrection and needs further refactoring to replace.
Updates #70907
Change-Id: I4c0e56c35745a225776bd611d026945efdaf96f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/667595 Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>