Revert "Make this compatible with PHP 7"

This reverts commit fa343a2.

Author: sebastianbergmann

src/StaticAnalysis/CodeUnitFindingVisitor.php

@@ -26,7 +26,6 @@
 use PhpParser\Node\Stmt\Interface_;
 use PhpParser\Node\Stmt\Trait_;
 use PhpParser\Node\UnionType;
-use PhpParser\NodeAbstract;
 use PhpParser\NodeTraverser;
 use PhpParser\NodeVisitorAbstract;
 use SebastianBergmann\Complexity\CyclomaticComplexityCalculatingVisitor;
@@ -316,10 +315,7 @@ private function intersectionTypeAsString(IntersectionType $node): string
         return implode('&', $types);
     }
 
-    /**
-     * @psalm-param Identifier|Name $node $node
-     */
-    private function typeAsString(NodeAbstract $node): string
+    private function typeAsString(Identifier|Name $node): string
     {
         if ($node instanceof Name) {
             return $node->toCodeString();