Teach conclass how to handle 32 bit values and deduplicate the code
between con32class and conclass.
Change-Id: I9c5eea31d443fd4c2ce700c6ea21e1d0bef665b0
Reviewed-on: https://go-review.googlesource.com/c/go/+/650938
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Joel Sing <joel@sing.id.au>