Indentation is removed from doc comments

[Gama11]

This is problematic if you have code examples in the docs, e.g.:

/**
	```
	function generatorWithoutReturn():Generator {
		php.Syntax.yield(1);
		return null;
	}
	```
**/

is currently turned into:

/**
	```
	function generatorWithoutReturn():Generator {
	php.Syntax.yield(1);
	return null;
	}
	```
**/

(from haxe\std\php\Generator.hx)