encoding/charmap: add IBM 037. Change-Id: Ida4aac5c3b3c12aa346e719a5f5ed631751f0bab Reviewed-on: https://go-review.googlesource.com/35530 TryBot-Result: Gobot Gobot <gobot@golang.org> Run-TryBot: Marcel van Lohuizen <mpvl@golang.org> Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>