Fixes findHandlerInXDataAMD64 to handle the return value of sort.Search
when the search fails to find anything. Otherwise, the value may later
be used as an index, causing an out of range error.
Fixes #64200
Change-Id: I4f92e76b3f4d4d5dbe5cbc707f808298c580afe1
Reviewed-on: https://go-review.googlesource.com/c/go/+/543076
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Quim Muntal <quimmuntal@gmail.com>