env/linux-arm-qemu: add gcc and go1.4.2
env/linux-arm-qemu: add gcc and go1.4.2

fixes golang/go#10018

Change-Id: Ia739f597fc1c84ecca05949fb83e7648077e5578
Reviewed-on: https://go-review.googlesource.com/6172
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/build,proppy/build,golang/build,proppy/build,golang/build,golang/build,evandbrown/build,proppy/build,evandbrown/build,proppy/build,evandbrown/build