slices: add cases for TestInsertPanics when there are values
For #64152
Change-Id: I32531aa8d147f4f10f6498f5ea1474555e93b6de
GitHub-Last-Rev:
48bb3bb05c6acc3761680a8a0eac9df9dfd154d3
GitHub-Pull-Request: golang/go#64180
Reviewed-on: https://go-review.googlesource.com/c/go/+/542535
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Jes Cok <xigua67damn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>