reflect: use cgo.Incomplete instead of go:notinheap in tests
go:notinheap will be replaced by runtime/internal/sys.NotInHeap, and for
longer term, we want to restrict all of its usages inside the runtime
package only.
Updates #46731
Change-Id: I267adc2a19f0dc8a1ed29b5b4aeec1a7dc7318d5
Reviewed-on: https://go-review.googlesource.com/c/go/+/421880
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>