Fix edge cases checking if namespaces use semicolons when converting to php-ast

[TysonAndre]

PHP-Parser doesn't tell you if a namespace with a block originally used semicolons.

lib/PhpParser/PrettyPrinterAbstract.php

• If all of the namespaces are not in the global namespace, use semicolons (Most common)
• If at least one is the global namespace, then convert to block style.

[nikic]

It probably makes sense to add an attribute for this in PHP-Parser.

[TysonAndre]

Right now, I'm checking the end line number of the namespace. If the end line number is smaller than any of the immediate descendants' end line numbers, this will assume it's namespace;, not namespace{}.

• Line comments don't seem to have (end) line numbers

An attribute would definitely help, in case of files with one-liners (namespace Foo; interface InterfaceOnSameLine{})