rsc: two-file program

Change-Id: I071598ce7d8b9c05dee2015ebf62bcf1c188a717
Reviewed-on: https://go-review.googlesource.com/3623
Reviewed-by: Russ Cox <rsc@golang.org>

rsc/greeting.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func greeting() {
+	fmt.Println("hello, git")
+}

rsc/main.go

@@ -0,0 +1,5 @@
+package main
+
+func main() {
+	greeting()
+}