Leading comment removed from consequent of ConditionalExpression

When a `ConditionalExpression` is modified, the printer may remove a leading comment from the consequent/left side of the expression. This does not happen to comments on the alternate/right side of the expression.

I created [this example](http://astexplorer.net/#/gist/0a3ad62148aeacd8efce2c2228a1bd07/a6e7b19b4810e24dd849abd6e845a4db85910e7b) to reproduce the issue using `jscodeshift` to transform the code.

Start with the AST Explorer reproduction linked in the issue and trace how the printer handles a modified ConditionalExpression, comparing the consequent/left side with the alternate/right side. Confirm the behavior with a focused regression test; done means modifying the expression preserves leading comments on both sides.

Written by the indexing model from the issue text.