Semi-automatic migration from package syscall to package {plan9,windows,unix}.
No builds attempted yet, but this gets a lot of noise behind us so subsequent
CLs will be more concise and easier to follow.
Subsequent CLs will have semantic content.

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/121520043

This CL copies to each package of go.sys the files from syscall it will need.
Different directories have different files, but these:
        mkall.sh
        str.go
        syscall.go
        mksyscall.pl
        race.go
        race0.go
        syscall_test.go
are copied to all three.
No changes yet, these are just copies. They are not ready to use yet:
package names are wrong, for starters. But this clean copy will make
it easier to follow the changes as the packages are enabled.

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/126960043

See http://golang.org/s/go1.4-syscall for background.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/123130043

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/44810044

See this thread for background:
https://groups.google.com/forum/#!topic/golang-dev/xG7vPi21r8g

R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/39440047

I edited the wrong README when cloning the empty repo to create the tools one.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/9486043

This subrepo is the ultimate home for some of the experimental components
being developed in go.exp now, and also existing pieces such as go vet.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/9481043

R=r
CC=golang-dev
https://golang.org/cl/6026043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5845057

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5572056