add test case for println

Makefile

@@ -130,6 +130,8 @@ test/example:
 
 	${CELL} -d -t riscv tests/examples/typecast.cell && ckb-debugger --bin typecast${exe} | grep "128-128"
 
+	${CELL} -d -t riscv tests/examples/println.cell && ckb-debugger --bin println${exe}
+
 	${CELL} -t riscv tests/examples/cell-data.cell && ckb-debugger --bin cell-data${exe}
 	${CELL} -t riscv tests/examples/inputs.cell && ckb-debugger --bin inputs${exe}
 	${CELL} -t riscv tests/examples/outputs.cell && ckb-debugger --bin outputs${exe}

tests/examples/println.cell

@@ -0,0 +1,15 @@
+import (
+	"debug"
+)
+
+func main() {
+	debug.Println("1")
+	debug.Println(1)
+	debug.Println(1u8)
+	debug.Println(1u16)
+	debug.Println(1u32)
+	debug.Println(1u64)
+	debug.Println(1u128)
+	debug.Println(1u256)
+	return 0
+}