PHP8: Static Method Lint Test

This commit adds a lint test to check the code for any static calls to a non-static function which throws a fatal error as of PHP 8.0.

setup/test/tests/test.staticmethods.php

@@ -0,0 +1,37 @@
+<?php
+require_once "class.test.php";
+
+class StaticMethods extends Test {
+    var $name = "Methods that should be static";
+
+    static function ignore3rdparty() {
+        return false;
+    }
+
+    function testStaticMethods() {
+        $scripts = static::getAllScripts();
+        $static_functions = array();
+        foreach ($scripts as $s) {
+            $matches = array();
+            preg_match_all('/^\s*(?:\/\*[^*]*\*\/)?\s*'
+                    .'(?:(?:private|public|protected|static|abstract)\s+)+'
+                    .'function\s+&?\s*([^(\s]+)\s*\(/m',
+                file_get_contents($s), $matches);
+            $static_functions = array_merge($static_functions, $matches[1]);
+        }
+        foreach (static::find_function_calls($scripts) as $call) {
+            list($file, $no, $line, $func) = $call;
+            if ((strpos($line, 'parent::'.$func) === false) &&
+                (strpos($line, 'Unpacker::'.$func) === false) &&
+                (strpos($line, '::'.$func) !== false) && !in_array($func, $static_functions)) {
+                $this->fail($file, $no, "$func: Function should be static");
+            }
+            else {
+                $this->pass();
+            }
+        }
+    }
+}
+
+return 'StaticMethods';
+?>