strconv: cleanup old compiler bits.TrailingZeros workaround
Since CL 599096 the compiler knows bits.TrailingZeros's maximum value
based on the input type size.
Since CL 603996 it knows it based on input's maximum value.
Change-Id: Ib0d6b15a3ba6894d3e7e12b79b387ddbffabe370
Reviewed-on: https://go-review.googlesource.com/c/go/+/618715
Auto-Submit: Robert Griesemer <gri@google.com>
Commit-Queue: Robert Griesemer <gri@google.com> Reviewed-by: Robert Griesemer <gri@google.com> Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org>