build: separate compiler and libs

compiler/cl/_testlibgo/sync/in.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"sync"
+)
+
+var once sync.Once
+
+func f(s string) {
+	once.Do(func() {
+		println(s)
+	})
+}
+
+func main() {
+	f("Do once")
+	f("Do twice")
+}