cmd/go/internal/version: print correct go version, vgo version

vendor/cmd/go/internal/version/version.go

diff --git a/vendor/cmd/go/internal/version/version.go b/vendor/cmd/go/internal/version/version.go
index c3f7d73..251ff72 100644
--- a/vendor/cmd/go/internal/version/version.go
+++ b/vendor/cmd/go/internal/version/version.go
@@ -10,8 +10,11 @@
 	"runtime"
 
 	"cmd/go/internal/base"
+	"cmd/go/internal/work"
 )
 
+const vgoVersion = "2018-02-20.1"
+
 var CmdVersion = &base.Command{
 	Run:       runVersion,
 	UsageLine: "version",
@@ -24,5 +27,5 @@
 		cmd.Usage()
 	}
 
-	fmt.Printf("go version %s %s/%s\n", runtime.Version(), runtime.GOOS, runtime.GOARCH)
+	fmt.Printf("go version %s %s/%s vgo:%s\n", work.RuntimeVersion, runtime.GOOS, runtime.GOARCH, vgoVersion)
 }

vendor/cmd/go/internal/work/build.go

diff --git a/vendor/cmd/go/internal/work/build.go b/vendor/cmd/go/internal/work/build.go
index a9274db..908faa1 100644
--- a/vendor/cmd/go/internal/work/build.go
+++ b/vendor/cmd/go/internal/work/build.go
@@ -274,6 +274,7 @@
 var pkgsFilter = func(pkgs []*load.Package) []*load.Package { return pkgs }
 
 var runtimeVersion = getRuntimeVersion()
+var RuntimeVersion = runtimeVersion
 
 func getRuntimeVersion() string {
 	data, err := ioutil.ReadFile(filepath.Join(cfg.GOROOT, "src/runtime/internal/sys/zversion.go"))