* PHP-8.1:
Fix GH-10008: Narrowing occurred during type inference of ZEND_ADD_ARRAY_ELEMENT
Fix type error on XSLTProcessor::transformToDoc return value with SimpleXML
The return type is wrong. You can also use this method with SimpleXML.
In fact, PHP provides a way that even third party libraries can hook
into its XML handling. Therefore, we cannot even use the
SimpleXML|DOMDocument|false union type as third party extensions may
extend the possibilities.
Broke in 8.1 in 1b35056a33.
Closes GH-12315.
Additionally normalize to using $namespace rather than $uri for
namespace parameters, including in XMLReader and XMLWriter. I went
with that one as it is currently used by DOM, SimpleXML and XSL --
and our DOM parameter names follow the DOM specification.
Closes GH-6295.
