Description:
------------
Using a non-compound name in a use statement results in a warning that 
states non-compound names in use statement would have no effect which 
isn't true as the following reproduce code shows.

Reproduce code:
---------------
<?php // a.php
namespace Test1;
function fooBar() { echo 'Test1::fooBar()' . PHP_EOL; }

namespace Test2;
use Test1;
Test1::fooBar();

<?php // b.php
namespace Test1;
function fooBar() { echo 'Test1::fooBar()' . PHP_EOL; }

namespace Test2;
Test1::fooBar();


Expected result:
----------------
No warning or same behavior with and without use statement.

Actual result:
--------------
Executing a.php results in "Warning: The use statement with non-compound 
name 'Test1' has no effect in [...]".
Executing b.php results in "Fatal error: Class 'Test2::Test1' not found 
in [...]".