* lang_php/analyze/foundation/graph_code_php.ml: fix
* lang_php/analyze/foundation/graph_code_php.ml: basic lookup namespace,
try with current qualifier
* tests/php/parsing/namespace_use.php: support in ast_php_simple
* lang_php/analyze/foundation/graph_code_php.ml: fix
* tests/php/semantic/namespace_use.php: test