cmd/compile: compute min's & max's limits from argument's limits inside flowLimit

cmd/compile: compute min's & max's limits from argument's limits inside flowLimit

Updates #68857

Change-Id: Ied07e656bba42f3b1b5f9b9f5442806aa2e7959b
Reviewed-on: https://go-review.googlesource.com/c/go/+/656157
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Jorropo <jorropo.pgm@gmail.com>