cmd/dist: enable GOARM>5 on NetBSD/ARM. Tested GOARM=6 on Raspberry Pi, and I found only a few tests that use sub-normal numbers fails. I have a patch to NetBSD kernel pending that fixes this issue (NetBSD kernel doesn't allow us to disable the Flush-to-Zero feature).
cmd/dist: enable GOARM>5 on NetBSD/ARM.
Tested GOARM=6 on Raspberry Pi, and I found only a few tests that
use sub-normal numbers fails. I have a patch to NetBSD kernel pending
that fixes this issue (NetBSD kernel doesn't allow us to disable the
Flush-to-Zero feature).

LGTM=jsing
R=golang-codereviews, jsing
CC=golang-codereviews
https://codereview.appspot.com/70730043

wesolows/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang-old,wesolows/golang,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old