The new error value proposal (https://golang.org/design/29934-error-values)
adds stack frame information to the errors produced by errors.New
and fmt.Errorf. This will break any test that compares errors
with reflect.DeepEqual.
This vet check finds any call to reflect.DeepEqual both of whose
arguments are of type error, or are of a type that can store
of value of type error.
Change-Id: I55939339344ed5b4f61557a7296734a710211918
Reviewed-on: https://go-review.googlesource.com/c/162939
Reviewed-by: Damien Neil <dneil@google.com>
ac7c11b94d