Backport "use function" fix to 1.4

Author: loilo

src/Token/Stream.php

@@ -176,6 +176,7 @@ protected function scan($sourceCode)
                     $name = 'CLASS_NAME_CONSTANT';
                 } elseif ($name == 'USE' && isset($tokens[$i+2][0]) && $tokens[$i+2][0] == T_FUNCTION) {
                     $name = 'USE_FUNCTION';
+                    $text .= $tokens[$i+1][1] . $tokens[$i+2][1];
                     $skip = 2;
                 }