runtime: add invalidptr=0 for TestGcZombieReporting

runtime: add invalidptr=0 for TestGcZombieReporting

pointers in zombies slice may cross-span, add invalidptr=0 for avoiding the badPointer check

Fixes #49613

Change-Id: Ifb1931922170e87e799e2e6081dc85dab3890205
Reviewed-on: https://go-review.googlesource.com/c/go/+/367044
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>