[analyzer] ignore 'dead_code' for this line action misplaces the ignore: dead_code comment.

[modulovalue]

Consider:

void main() {
  MapEntry(
    throw 0,
    2,
  );
}

Notice that, as expected, the second argument to the MapEntry constructor invocation is being reported as dead code.

To reproduce:

1. Move the caret to the line containing the 2.
2. Invoke the "ignore 'dead_code' for this line" action.
3. Notice how the // ignore: dead_code line will be placed in a position that does not have the intended effect. It will be placed between void main() { and MapEntry( and not between throw 0, and 2,.

I expected the ignore 'dead_code' for this line action to place the comment in a position that causes the dead code warning to be disabled, that is: