build: separate compiler and libs

compiler/cl/_testrt/alloca/in.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+	"github.com/goplus/llgo/c"
+)
+
+func main() {
+	s := c.Str("Hi\n")
+	s2 := c.Alloca(4)
+	c.Memcpy(s2, c.Pointer(s), 4)
+	c.Printf(c.Str("%s"), s2)
+}