Merge the signed and unsigned generic functions.
The only implementation difference between the two is:
n > 0 vs n != 0 check.
For unsigned numbers n > 0 == n != 0 and we infact optimize
the first to the second.
Change-Id: Ia2f6c3e3d4eb098d98f85e06dc2e81baa60bad4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/726720 Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>