Arch Linux

Description:
One of the strengh of go is the ability to build executable for other platform/architectur thant the one on which we are doing the build:
GOOS=windows GOARCH=386 go build test.go
will build test.go for windows in 32 bits.

But to be able to do it, the go runtime have to be compiled with these options first. here is an extract of the go mailing list :
"after the initial go core compile/install using './all.bash', you'd want to run `GOOS=windows GOARCH=386 ./make.bash` (for this example) to build the windows-386 compiler target"

So it would be really great if the go package could be compiled with all target to be able to compile easily on all platform target fro archlinux.

Additional info:
* package version(s)
2:1-6
* config and/or log files etc.

Steps to reproduce:

Try to build a go binary for Windows
GOOS=windows GOARCH=386 go build test.go

Here is the error :
go build runtime: exec: "/usr/lib/go/pkg/tool/linux_amd64/8g": stat /usr/lib/go/pkg/tool/linux_amd64/8g: no such file or directory