Why does Kotlin 1.3.60 push a constant 0 to the operand stack and then store it away before printing?

fun hello() {
    println("hello")
}

Bytecode:

public static final void hello();
    Code:
       0: ldc           #7                  // String hello
       2: astore_0
       3: iconst_0
       4: istore_1
       5: getstatic     #13                 // Field java/lang/System.out:Ljava/io/PrintStream;
       8: aload_0
       9: invokevirtual #19                 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
      12: return

I would expect that to be the return value of main

Make sure you're making release build, debug one has lots of silly operations for helping debbuger

I'm using command line

kotlinc-jvm

1.3.60 and

kotlin

1.3.60-release-155. But okay, it's probably nothing special

It's for debugger: https://kotlinlang.slack.com/archives/C7L3JB43G/p1558022163043700?thread_ts=1557907293.041100&cid=C7L3JB43G