Improve replace + DCE w. surrounding blocks

When Babili is run with replacements, such as to replace `console.log` with empty function, but there's surrounding block, that block is never removed:

```
if (!this.smth) {
console.log("foo bar");
}
```

No source file or test is named. Reproduce the Babili replacement example with the surrounding if block, then trace the replacement and dead-code-elimination passes; done means the block is removed when its only statement becomes an empty function call.

Written by the indexing model from the issue text.