Now that the compiler handles constant 64-bit divisions
without function calls on 32-bit systems, we no longer need
to maintain and test a bad custom implementation of 64-bit division.
Change-Id: If28807ad4f86507267ae69bc8f0b09ec18e98b66
Reviewed-on: https://go-review.googlesource.com/c/go/+/716463
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Russ Cox <rsc@golang.org> Reviewed-by: Alan Donovan <adonovan@google.com>